Tap here to go to the mobile version of the site.
Your Firefox is out of date and may contain a security risk! Upgrade Firefox

Support Forum

firefox 4 this page requires a plugin that can only run in 32-bit mode


I get this message on new Firefox 4 when trying to use regular gmail website. What's going on?

Additional System Details

This happened

Every time Firefox opened

This started when...

firefox 4

Installed Plug-ins

  • Picasa plugin.
  • The Flip4Mac WMV Plugin allows you to view Windows Media content using QuickTime.
  • DivX Web Player version
  • Version
  • iPhoto6
  • 4.0.51204.0
  • The QuickTime Plugin allows you to view a wide variety of multimedia content in web pages. For more information, visit the QuickTime Web site.
  • Java Plug-In 2 for NPAPI Browsers
  • Shockwave Flash 10.2 r152


  • User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:2.0) Gecko/20100101 Firefox/4.0

More Information

chalcopis 0 solutions 2 answers

I use a MacBook Pro and found a solution that appears to work for me.

(1) Close Firefox. (2) Go to the Application folder with your OS X applications and find the Firefox icon. (3) Right-click on the icon. If your mouse does not support right-clicking, hold down the ctrl key and click on the icon. (4) Select Get Info from the drop-down menu. (5) In the info screen, check the box next to Open in 32-bit mode. (6) Close the info screen and launch Firefox.

The message about 32-bit mode has not appeared since I did this.

chalcopis 0 solutions 2 answers

Since my previous post, I have had a recurrence of the problem, so this was not a permanent fix. It appears that Firefox is trying to start a plug-in that helps with replying to messages in Yahoo Mail, which is where this comes up. So, I hope someone will come up with something more suitable.

captin007 0 solutions 1 answers

I too have a Macbook Pro and experience the same problems with Hotmail.

JonG 0 solutions 1 answers

I discovered that WMV can be run in 64-bit by adding Flip4Mac WMV application. There is a free basic version to download from www.telestream.net/flip4mac-wmv/overview.htm It is an addon to Quicktime and seems to work. Confusingly, opening Flip4Mac in System Preferences shows 'Use Flip4Mac WMV Browser plug-in' ticked but greyed out. Flip4Mac avoids restarting in 32-bit or setting Firefox to 32-bit all the time [Finder, Applications, (Right click) Firefox, Get Info, (Tick) Open in 32-bit]

bmahf 0 solutions 1 answers

I am getting the same issue. I am running on Max OS X 10.6.7 on a Macbook Pro with Firefox 4.0.1. I wasn't getting this error before going to Firefox 4, but now I get this all the time while using Hotmail. I also use Gmail but don't get this error there. I am seeing some references to installing Flip4Mac, but I'm not so sure that this is my problem, since the page I'm on doesn't seem to have anything to do with WMV files. Does anyone have a fix for this yet?

  • Top 10 Contributor
  • Moderator
10758 solutions 96836 answers

Helpful Reply

Hotmail probably uses Silverlight to upload attachments. So that plugin may be causing it in this case.

ariklin 0 solutions 3 answers

Helpful Reply

For me it was Browser Plus plug from Yahoo that was causing my problem. I uninstalled and so far so good - the error hasn't returned.