Quicktime Problem

User Help for Mozilla Firefox
Posts: 6
Joined: November 11th, 2007, 2:06 pm

Post Posted March 23rd, 2008, 7:19 pm

I don't know if it's Firefox or Quicktime itself but every time I run a site that has Quicktime, I get this message: Qicktime error #0.

Then I get this: 'The plugin performed an illegal operation. You are strongly advised to restart Firefox.'

I've already checked the Quicktime issue thread and I have gone over the MIME settings and nothing seems to be out of place. Quicktime works just fine in IE however.

Posts: 6
Joined: November 11th, 2007, 2:06 pm

Post Posted April 21st, 2008, 12:01 pm

Can someone please help me with this issue? I have uninstalled, reinstalled, and updated since posting this and I still get the same message whenever I run a file that uses Quicktime in Firefox. I have no idea how to resolve this issue anymore.


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Joined: April 23rd, 2003, 11:47 am

Post Posted April 21st, 2008, 1:29 pm

Did this problem start when you updated QuickTime? What is your Quicktime version? What is your Windows version? Do you also have ITunes installed?

In any case, you can try resetting the Quicktime plugins: ... er_plugins

You could also try a google search on the exact error message. Was it "Quicktime failed to initialize. error #0"? According to this Opera forum topic from 2. March 2008
I did a Google search for "quicktime failed to initialize. error #0". Quite a few people have the same problem after upgrading to Quicktime 7.4.1. It seems some of them have had success with uninstalling Quicktime and then reinstalling it again.

Here is another solution, from ... ror-0.html
Sunday, March 16, 2008
QuickTime failed to initialize. Error # 0, With Firefox and Win2k3 server

I recently started getting this message in Firefox:

QuickTime failed to initialize. Error # 0
Please make sure QuickTime is properly installed on this computer.

It seems it's caused by launching Firefox in WinXP compatibility mode, which I did in order to be able to use Rhapsody's music service, since they prevent it from running under Win2k3. Yucko. In any case, I searched over the web and nobody else had figured out why Quicktime was crashing this way. Perhaps there are other causes, but this one fixed it for me. I didn't even have to reinstall Quicktime.
You can see if you are running Firefox in Compatibility Mode by looking at the properties of firefox.exe or the properties of the shortcut you use to start Firefox.

Here are some other forum threads you can look through to see if anything helps (downgrading to an earlier Quicktime version seems to work but should be a last resort, due to security issues with older versions): ... ID=1259400 ... ID=7051614 ... &forumId=1
Alice Wyman


Post Posted March 27th, 2009, 5:10 pm

I've had the same issue, and Dan's last post (a downgrade to an older version) in the link Alice posted above ... &forumId=1
has resolved it.

But under some circumstances version 7.2 of QT has a security bug.


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Post Posted March 31st, 2009, 4:48 am

(For the record)

This thread is a year old. Instructions for updating, configuring, and resetting the QuickTime browser plugins are outlined here:

QuickTime 7.2 was released back in July 2007 and includes many security vulnerabilities fixed in QuickTime 7.3 (released 05 Nov 2007) through QuickTime 7.6 (released 21 Jan 2009).
Ref: Apple security updates (current) Apple security updates (25-Jan-2005 to 21-Dec-2007)
Vulnerability Report: Apple QuickTime 7.x ( advisories)
Alice Wyman


Post Posted November 19th, 2009, 8:05 am

having same problem today ... after i win XP auto update ....


Post Posted December 17th, 2009, 6:00 pm

Having the exact same problem. I've tried deleting the QT plugins, didn't work. The Windows Cleanup Utility didn't work. Downgraded to a lower version, didn't work. Compatibility mode has never been checked in the first place. (I checked anyways just in case.) Still broked. :(


Post Posted March 10th, 2010, 9:12 pm

I've only just noticed the same problem with the exception it says ''Quicktime failed to initialize Error #0'' it doesn't say anyting about being advised to close Firefox but after I click ok it does it anyway (if I don't click ok then it continues to work in it's usual manner, so far it has only done it with Facebook Chat and although I was simultaneously streaming a tv show on 4od I don't believe this to be the problem. I haven't encountered this problem before and I believe my Quicktime is fully up to date (possibly version 10.???) the only thing that's changed really is that I've recently done some unrelated windows updates and updated Firefox, so my guess it's a compatibility issue with Firefox. I'm sure someone will fix this issue eventually but there is a temporary fix just go into Firefox's ad ons and disable the quicktime plug in ;)


Post Posted June 10th, 2010, 12:09 pm the same issue....

In my case it was due to the de-installation of the Apple Application Support, a piece of Software that comes with iTunes.

I fixed it by:
Downloading iTunes 9
Use WinRAR or WinZip on the Exe File
Run/Extract the AppleApplicationSupport.msi
Install the thing, reassociate the files when Quicktime asks you
Restart PC
Done :)


Post Posted July 24th, 2010, 7:02 am

Installing the Apple Application Support fixed it for me.

Thanks Guest!

Jim Beer

Post Posted January 27th, 2011, 8:40 pm

Thank You Guest! The Apple Application Support tip worked like a I learned you can apply winzip to an .exe file. Who knew? Just a flawless win. Btw, after googling/reading tips for hours, no other suggestion passed muster..

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