517619 - Firefox tries to download unknown file instead of playing movie

Status: RESOLVED WORKSFORME

(Firefox :: General, defect)

Description

[Valentin Dragan]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.3) Gecko/20090824 Firefox/3.5.3
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.3) Gecko/20090824 Firefox/3.5.3

Sometimes - (never immediately after starting the browser BUT only after the browser has been used for quite a while) accessing any YouTube video with the link like the one above (NOT http://www.youtube.com/watch?v=43scrCjAVHc BUT http://www.youtube.com/v/43scrCjAVHc )would bring up the file download dialog instead of opening a page that should play the requested video to the maximum size....
When the bug occurs you can download a useless .swf file of 1k or less...

Reproducible: Couldn't Reproduce

Actual Results:  
Firefox brings up the download dialog box then downloads a uselss small swf file

Expected Results:  
The page should play a swf movie adapted to the page's size

Addons used:

ColorZilla
Blank Canvas
Image Zoom
Measure It
Search Status
Xmarks

Comment 1

[Tyler Downer [He/Him]]

Do you have flash installed? Make sure you have the firefox version, and not just the IE

Comment 2

[Valentin Dragan]

I am only using Firefox (I'm using IE only for webmaster testing purposes);
Flash IS installed - as I said - it happens sometimes - rest of the times works fine...

Comment 3

[Valentin Dragan]

When the bug occurs I can see a youtube video using the regular http://www.youtube.com/watch?v=VIDEO link - the problem is only when using http://www.youtube.com/v/VIDEO link...

Comment 4

[Valentin Dragan]

Attachment: This is what firefox download instead of playing the movie

Comment 5

[Matthias Versen [:Matti]]

This can happen if the server sends a wrong content-type header for the file.
I assume that youtube is using a serverfarm and you get this only for some servers.

To be sure that this is a valid bug we need a packet trace from example from Wireshark for such a failed request or create a http log :
https://developer.mozilla.org/en/HTTP_Logging

Be sure that you cleared the Firefox cache before you try to create the log.

Comment 6

[Valentin Dragan]

I'm gonna have to wait for the bug to "bug" me again;
Though - when I have the problem restarting the browser solves the problem 100% - so, I guess it is not a server side issue;

I gonna be back  with details when it happens again....

Comment 7

[Valentin Dragan]

I cannot use the HTTP logging as it requires a browser restart - the browser restart will clear the bug also - and, as I said, I do not know how to reproduce it - the thing is I have to :"catch" the bug  :) ;

I have attached a video showing the problem

Please let me know and I'll assist you with further details...

Comment 8

[Valentin Dragan]

Attachment: Error occurrence

The video contains comments regarding the issue.

Comment 9

[Valentin Dragan]

The BUG occures (once it happens in a Firefox session) every time you try to access a file like http://mysite/myFile.swf ;
You have to restart the browser for the things to get back to normal...

Comment 10

[Matthias Versen [:Matti]]

The response is cached, if you clear the disk cache it would work again.
Seamonkey1.X contains a different download dialog which would show the reason why Gecko wants to download this file but this additional information got removed in the Firefox download dialog.

Comment 11

[Valentin Dragan]

I do not know what you mean by "the response is cached" - and, if what you are offering is a workaround, I already have one - that is restarting the browser;

Comment 12

[Tyler Downer [He/Him]]

Reporter, are you still seeing this issue with Firefox 3.6.12 or later in safe mode? If not, please close. These links can help you in your testing.
http://support.mozilla.com/kb/Safe+Mode
http://support.mozilla.com/kb/Managing+profiles
Also, please consider using the most recent Firefox 4 beta build, your bug may be resolved there.