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The register button for our ASP.net form, which uses the __postback function stopped working on IE 11, from the developer console, it shows:
DOM7011: The code on this page disabled back and forward caching. For more information, see: http://go.microsoft.com/fwlink/?LinkID=291337.
Does anyone know how to get around with this? What is this caching thing and why does it mess up forms. I seen similar complaints about this from others.
This issue occurs if the server sends a "Cache-control:no-store" header or sends a "Cache-control:no-cache" header.
I have seen exactly the same error, also with IE11. In my case the issue occurred when user clicked <button> element, which was inside <form> tags.
The issue was remedied, by placing the <button> outside of <form> tags.
This error occurred for me when using window.location.reload(). Replacing with window.location = window.location.href solved the problem.
I faced the same issue before.
I cleared all the IE caches/browsing history/cookies & re-launch IE. It works after caches removed.
You may have a try. :)
In my case, this exception was being caused by an unsecure ajax call on an SSL enabled site. Specifically: my url was 'http://...' instead of 'https://...'. I just replaced it with '//...'.
To me, the error was misleading, and hopefully this may help anyone landing here after searching for the same error.
I run into this when click on a html , it is fixed by adding type = "button" attribute.
I got the same console warning, when an ajax request was firing, so my form was also not working properly.
I disabled caching on the server's ajax call with the following response headers:
Cache-Control: no-cache, no-store, must-revalidate
Expires: -1
Pragma: no-cache
After this, the form was working. Refer to the server language (c#, php, java etc) you are using on how to add these response headers.
I had a similar problem on Internet Explorer, and got the same error number. The culprit was an HTML comment. I know it sounds unbelievable, so here is the story.
I saw a series of 6 articles on the Internet. I liked them, so I decided to download the 6 Web-Pages and store them on my Hard Drive. At the top of each page, was a couple of HTML <a> Tags, that would allow you to go to the next article or the previous article. So I changed the href attribute to point to the next folder on my Hard Drive, instead of the next URL on the Internet.
After all of the links had been re-directed, the Browser refused to display any of the Web-Pages when I clicked on the Links. The message in the Console was the Error Number that was mentioned at the top of this page.
However, the real problem was a Comment. Whenever you download a Web-Page using Google Chrome, the Chrome Browser inserts a Comment at the very top of the page that includes the URL of the location that you got the Web-Page from. After I removed the Comment at the top of each one of the 6 Pages, all of the Links worked fine ( although I continued to get the same Error Message in the Console. )
Go to
Tools > Compatibility View settings > Uncheck the option "Display intranet sites in Compatibility View".
Click on Close. It may re-launch the page and then your problem would be resolved.
Basically in my error log i see lots of:
mysite.com/undefined (with referer coming from random pages of the website)
User-Agent: Mozilla/5.0 (Windows NT 6.0) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.89 Safari/537.1
(and some other user agent)
I have of course checked HTML or DOM for links with /undefined or something like that and there is just nothing. I have checked network tab with developer tools and on those page nothing requests /undefined (with my chrome).
I have then setted a javascript logger to save any error that come up. And in the log there isn't nothing that throws undefined or something like that...
This is driving me crazy. Of course if i go on tihs page with my chrome, javascript doesn't print any error
Notice: i have read everything here
Edit
Notice2: Beside that javascript error logger I have added an eventlistener (as explained in the answer linked)
$("body").on("click", "a[href$='undefined']", function() {
window.onerror('Bad link: ' + $(this).html()); //alert home base
});
And this never get triggered. (I have tested it with a manual /undefined link and the logger works)
Also I found this topic on google groups. Webmaster there are experiencing the same problem but no one has managed to nail down to the cause.
Maybe it's some extension on chrome or any other browser that causes this requests.
Presumably you are using window.onerror and logging an error in that function.
If a javascript error happens on a different domain (e.g. from some social buttons, an iframe, a cross-domain javascript, or possibly a browser extension), window.onerror could actually betray sensitive information in the error report. So for security reasons, cross-domain errors will still call the function, but all the parameters (including the url) will be undefined, and the message will just be a generic "Script error." I would guess you are having cross domain errors, and they're being logged as undefined.
Take another look at that Google Group thread you linked to. Just recently one of the members managed to figure a way to disable the plugin/malware that appears to be causing the errors:
To disable the malware and stop "undefiend" requests, apply this to
every page with a search field on your site:
<script type="text/javascript">
window.suggestmeyes_loaded = true;
</script>
It sounds like this is most likely an ajax request using "/" + variable and variable happens to be undefined instead of say user. Are you using a library for your AJAX calls? perhaps you could try to catch the invalid url in there as well.
When I click "Print" using the jQuery Print Preview Plugin the following error pops up and Firebug:
Error: Permission denied to access property 'name'
if (window.frames[i].name == "print-frame") {
I am not sure exactly what it means or how to correct it.
There is a way around this that will solve this problem and work properly with all major browsers. This solution was found by Derick over on the Github page for jQuery Print Preview.
Here is the solution, around line 44 you will see the following code:
// The frame lives
for (var i=0; i < window.frames.length; i++) {
if (window.frames[i].name == "print-frame") {
var print_frame_ref = window.frames[i].document;
break;
}
}
Replace the above code with this:
print_frame_ref = print_frame[0].contentWindow.document;
issue solved.
Here is the error in Chrome, I expect this makes it clear?
Unsafe JavaScript attempt to access frame with URL http://s7.addthis.com/static/r07/sh090.html#iit=1341762779832&tmr=load%3D1341762779182%26core%3D1341762779520%26main%3D1341762779826%26ifr%3D1341762779833&cb=0&cdn=0&chr=UTF-8&kw=&ab=-&dh=www.ubhape2.com&dr=http%3A%2F%2Fstackoverflow.com%2Fquestions%2F11384440%2Ferror-permission-denied-jquery-print-preview&du=http%3A%2F%2Fwww.ubhape2.com%2Ftest-print.html&dt=TEST%20Page&md=0&cap=tc%3D0%26ab%3D0&inst=1&irt=0&jsl=33&lng=en-US&ogt=&pc=men&pub=ra-4dfb00d56c76d2a5&ssl=0&sid=4ff9acdb1a41cc60&srd=0&srf=0.02&srp=0.2&srl=1&srx=1&ver=300&xck=0&xtr=0&og=&rev=114791&ct=1&xld=1&xd=1 from frame with URL http://www.ubhape2.com/test-print.html. Domains, protocols and ports must match.
Your page is located on ww.ubhape2.com and you are accessing a frame on s7.addthis.com
To fix this problem, change this line
<script type="text/javascript" src="https://s7.addthis.com/js/300/addthis_widget.js#pubid=ra-4dfb00d56c76d2a5"></script>
To point to the copied script on your site.
You will also have to edit that script to only access your own site.
This is an example of XSS or cross site scripting.
My question then turns into can I edit the jQuery Print Preview Script
to prevent the conflict from happening?
No.
The point of the error is that the javascript is running in the context of another party, and you can't "inject" your code into it.
This is enforced by the browser.
If it was not enforced then every user on the internet would have had their machines compromised.
Read up on a google search of XSS to find out more
However,
If you host the javascript (and thus the iframe) on your server than the issue goes away. It is your code (and your iframe) to do with as you wish.
Since 12 june 2012 11:20 TU, I see very weirds errors in my varnish/apache logs.
Sometimes, when a user has requested one page, several seconds later I see a similar request but the all string after the last / in the url has been replaced by "undefined".
Example:
http://example.com/foo/bar triggers a http://example.com/foo/undefined request.
Of course theses "undefined" pages does not exist and my 404 page is returned instead (which is a custom page with a standard layout, not a classic apache 404)
This happens with any pages (from the homepage to the deepest)
with various browsers, (mostly Chrome 19, but also firefox 3.5 to 12, IE 8/9...) but only 1% of the trafic.
The headers sent by these request are classic headers (and there is no ajax headers).
For a given ip, this seems occur randomly: sometimes at the first page visited, sometimes on a random page during the visit, sometimes several pages during the visit...
Of course it looks like a javascript problem (I'm using jquery 1.7.2 hosted by google), but I've absolutely nothing changed in the js/html or the server configuration since several days and I never saw this kind of error before. And of course, there is no such links in the html.
I also noticed some interesting facts:
the undefined requests are never found as referer of another pages, but instead the "real" pages were used as referer for the following request of the same IP (the user has the ability to use the classic menu on the 404 page)
I did not see any trace of these pages in Google Analytics, so I assume no javascript has been executed (tracker exists on all pages including 404)
nobody has contacted us about this, even when I invoked the problem in the social networks of the website
most of the users continue the visit after that
All theses facts make me think the problem occurs silently in the browers, probably triggered by a buggy add-on, antivirus, a browser bar or a crappy manufacturer soft integrated in browsers updated yesterday (but I didn't find any add-on released yesterday for chrome, firefox and IE).
Is anyone here has noticed the same issue, or have a more complete explanation?
There is no simple straight answer.
You are going to have to debug this and it is probably JavaScript due to the 'undefined' word in the URL. However it doesn't have to be AJAX, it could be JavaScript creating any URL that is automatically resolved by the browser (e.g. JavaScript that sets the src attribute on an image tag, setting a css-image attribute, etc). I use Firefox with Firebug installed most of the time, so my directions will be with that in mind.
Firebug Initial Setup
Skip this if you already know how to use Firebug.
After the installs and restarting Firefox for Firebug, you are going to have to enable most of Firebug's 'panels'. To open Firebug there will be a little fire bug/insect looking thing in the top right corner of your browser or you can press F12. Click through the Firebug tabs 'Console', 'Script', 'Net' and enable them by opening them up and reading the panel's information. You might have to refresh the page to get them working properly.
Debugging User Interaction
Navigate to one of the pages that has the issue with Firebug open and the Net panel active. In the Net panel there will be a few options: 'Clear', 'Persist', 'All', 'Html', etc. Make sure ALL is selected. Don't do anything on the page and try not to mouse over anything on it. Look through the requests. The request for the invalid URL will be red and probably have a status of 404 Not Found (or similar).
See it on load? Skip to the next part.
Don't see it on initial load? Start using your page and continue here.
Start clicking on every feature, mouse over everything, etc. Keep your eyes on the Net panel and watch for a requests that fail. You might have to be creative, but continue using your application till you see your browser make an invalid request. If the page makes many requests, feel free to hit the 'Clear' button on the top left of the Net panel to clear it up a bit.
If you submit the page and see a failed request go out really quick but then lose it because the next page loads, enable persistence by clicking 'Persist' in the top left of the Net panel.
Once it does, and it should, consider what you did to make that happen. See if you can make it happen again. After you figure out what user interaction is making it happen, dive into that code and start looking for things that are making invalid requests.
You can use the Script tab to setup breakpoints in your JavaScript and step through them. Investigate event handlers done via $(elemment).bind/click/focus/etc or from old school event attributes like onclick=""/onfocus="" etc.
If the request is happening as soon as the page loads
This is going to be a little harder to peg down. You will need to go to the Script tab and start adding break points to every script that runs on load. You do this by clicking on the left side of the line of JavaScript.
Reload your page and your break points should stop the browser from loading the page. Press the 'Continue' button on the script panel. Go to your net panel and see if your request was made, continue till it is found. You can use this to narrow down where the request is being made from by slowly adding more and more break points and then stepping into and out of functions.
What you are looking for in your code
Something that is similar to the following:
var url = workingUrl + someObject['someProperty'];
var url = workingUrl + someObject.someProperty;
Keep in mind that someObject might be an object {}, an array [], or any of the internal browser types. The point is that a property will be accessed that doesn't exist.
I don't see any 404/red requests
Then whatever is causing it isn't being triggered by your tests. Try using more things. The point is you should be able to make the request happen somehow. You just don't know yet. It has to show up in the Net panel. The only time it won't is when you aren't doing whatever triggers it.
Conclusion
There is no super easy way to peg down what exactly is going on. However using the methods I outlined you should be at least be able to get close. It is probably something you aren't even considering.
Based on this post, I reverse-engineered the "Complitly" Chrome Plugin/malware, and found that this extension is injecting an "improved autocomplete" feature that was throwing "undefined" requests at every site that has a input text field with NAME or ID of "search", "q" and many others.
I found also that the enable.js file (one of complitly files) were checking a global variable called "suggestmeyes_loaded" to see if it's already loaded (like a Singleton). So, setting this variable to false disables the plugin.
To disable the malware and stop "undefined" requests, apply this to every page with a search field on your site:
<script type="text/javascript">
window.suggestmeyes_loaded = true;
</script>
This malware also redirects your users to a "searchcompletion.com" site, sometimes showing competitors ADS. So, it should be taken seriously.
You have correctly established that the undefined relates to a JavaScript problem and if your site users haven't complained about seeing error pages, you could check the following.
If JavaScript is used to set or change image locations, it sometimes happens that an undefined makes its way into the URI.
When that happens, the browser will happily try to load the image (no AJAX headers), but it will leave hints: it sets a particular Accept: header; instead of text/html, text/xml, ... it will use image/jpeg, image/png, ....
Once such a header is confirmed, you have narrowed down the problem to images only. Finding the root cause will possibly take some time though :)
Update
To help debugging you could override $.fn.attr() and invoke the debugger when something is being assigned to undefined. Something like this:
(function($, undefined) {
var $attr = $.fn.attr;
$.fn.attr = function(attributeName, value) {
var v = attributeName === 'src' ? value : attributeName.src;
if (v === 'undefined') {
alert("Setting src to undefined");
}
return $attr(attributeName, value);
}
}(jQuery));
Some facts that have been established, especially in this thread: http://productforums.google.com/forum/#!msg/chrome/G1snYHaHSOc/p8RLCohxz2kJ
it happens on pages that have no javascript at all.
this proves that it is not an on-page programming error
the user is unaware of the issue and continues to browse quite happily.
it happens a few seconds after the person visits the page.
it doesn't happen to everybody.
happens on multiple browsers (Chrome, IE, Firefox, Mobile Safari, Opera)
happens on multiple operating systems (Linux, Android, NT)
happens on multiple web servers (IIS, Nginx, Apache)
I have one case of googlebot following the link and claiming the same referrer. They may just be trying to be clever and the browser communicated it to the mothership who then set out a bot to investigate.
I am fairly convinced by the proposal that it is caused by plugins. Complitly is one, but that doesn't support Opera. There many be others.
Though the mobile browsers weigh against the plugin theory.
Sysadmins have reported a major drop off by adding some javascript on the page to trick Complitly into thinking it is already initialized.
Here's my solution for nginx:
location ~ undefined/?$ {
return 204;
}
This returns "yeah okay, but no content for you".
If you are on website.com/some/page and you (somehow) navigate to website.com/some/page/undefined the browser will show the URL as changed but will not even do a page reload. The previous page will stay as it was in the window.
If for some reason this is something experienced by users then they will have a clean noop experience and it will not disturb whatever they were doing.
This sounds like a race condition where a variable is not getting properly initialized before getting used. Considering this is not an AJAX issue according to your comments, there will be a couple of ways of figuring this out, listed below.
Hookup a Javascript exception Logger: this will help you catch just about all random javascript exceptions in your log. Most of the time programmatic errors will bubble up here. Put it before any scripts. You will need to catch these on the server and print them to your logs for analysis later. This is your first line of defense. Here is an example:
window.onerror = function(m,f,l) {
var e = window.encodeURIComponent;
new Image().src = "/jslog?msg=" + e(m) + "&filename=" + e(f) + "&line=" + e(l) + "&url=" + e(window.location.href);
};
Search for window.location: for each of these instances you should add logging or check for undefined concats/appenders to your window.location. For example:
function myCode(loc) {
// window.location.href = loc; // old
typeof loc === 'undefined' && window.onerror(...); //new
window.location.href = loc; //new
}
or the slightly cleaner:
window.setLocation = function(url) {
/undefined/.test(url) ?
window.onerror(...) : window.location.href = url;
}
function myCode(loc) {
//window.location.href = loc; //old
window.setLocation(loc); //new
}
If you are interested in getting stacktraces at this stage take a look at: https://github.com/eriwen/javascript-stacktrace
Grab all unhandled undefined links: Besides window.location The only thing left are the DOM links themselves. The third step is to check all unhandeled DOM links for your invalid URL pattern (you can attach this right after jQuery finishes loading, earlier better):
$("body").on("click", "a[href$='undefined']", function() {
window.onerror('Bad link: ' + $(this).html()); //alert home base
});
Hope this is helpful. Happy debugging.
I'm wondering if this might be an adblocker issue. When I search through the logs by IP address it appears that every request by a particular user to /folder/page.html is followed by a request to /folder/undefined
I don't know if this helps, but my website is replacing one particular *.webp image file with undefined after it's loaded in multiple browsers. Is your site hosting webp images?
I had a similar problem (but with /null 404 errors in the console) that #andrew-martinez's answer helped me to resolve.
Turns out that I was using img tags with an empty src field:
<img src="" alt="My image" data-src="/images/my-image.jpg">
My idea was to prevent browser from loading the image at page load to manually load later by setting the src attribute from the data-src attribute with javascript (lazy loading). But when combined with iDangerous Swiper, that method caused the error.
The project I'm working on uses a window.onerror event handler to report user problems. I've noticed a single user that just cannot seem to load the Google Analytics script. Our site doesn't see a lot of traffic so I'm not sure how widespread this is, but so far it seems to just effect one user.
His user agent is: "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.17) Gecko/20080829 Firefox/2.0.0.17".
The error message Firefox gives is: "Error loading script".
Additional note: The site references several other javascript files. However, the analytics reference is the only one to an external domain and the only script reference at the bottom of the page, just before the closing body tag.
Has anybody else run across this, or have any idea what could be the issue? Thanks!
This problem occurs when leaving a page in Firefox before all scripts have finished loading. So I assume that it is safe to ignore the error.
You don't see this error in the Firefox error console, but you can make it visible by binding an alert to the window.onerror event. Then you will be able to see the alert box for a small amount of time and get the following error in the error console:
[11:35:57.428] uncaught exception: [Exception... "prompt aborted by user" nsresult: "0x80040111 (NS_ERROR_NOT_AVAILABLE)" location: "JS frame :: resource:///components/nsPrompter.js :: openTabPrompt :: line 462" data: no]
I'm using the following check to ignore this error in my onerror handler:
if (navigator.userAgent.search('Firefox') != -1 && message === 'Error loading script') {
// Firefox generates this error when leaving a page before all scripts have finished loading
return;
}
This is a rather random guess, but I wonder if the user is using an add-on like NoScript to control script execution and is not allowing scripts from Google Analytics to run. I know this is possible because it's what I do :) I don't know if that would show up as the error you're seeing.
I have a site with over 80 pages, all that employ JavaScript error trapping. My site serves well over 2000 pages a day and I get about ten "Error loading script" scripting errors each day from Firefox browsers. It is beginning to really annoy me and I am becoming convinced that it is a problem in Firefox.
I can discount the NOSCRIPT suggestion because the script loads in the head of my pages where there are no NOSCRIPT tags.
I can discount the 'external domain' suggestion because I have two sites that suffer this problem and in both cases the JS library files are located on the sites own server.
I have carefully checked every library file and web page using JavaScript Lint and I have discovered scripting errors and questionable scripting techniques. All these problems have been corrected but this has not provided any sort of cure to the "Error loading script" problem.
My pages do load several JavaScript library files that do not have this problem and the only difference is the size of the files. Most of the files are under 5KB but the problem file is 17KB.
Could the size of the library file be the problem?
Aagh!
We had the same issue and after examining our CDN logs, we discovered that Firefox triggers the onerror event when a script returns with HTTP status "304 Not Modified", so a cache hit. In fact, Firefox (tested with Firefox 12 at time of this writing), seems to trigger onerror event for all HTTP statuses except '200 Ok'. Other browsers behaved differently in our experiment: Chrome (19) triggered onerror only on '407 Proxy Authentication Required' and Opera (12) on 100, 101, 204, 4xx and 5xx.
I'm sure this is long resolved.. but to anyone who stumbles across this page: this error is triggered by firefox when an external script fails to load (it's easy to find the code that triggers this in the source code). We were catching these errors on our site and it turned out that we were returning 404s for the script, so I suggest looking at your logs as one possibly source of this error.