Firefox 3 Issues with MobileMe? Check Ubiquity Plugin Compatibility

It seems that not just I, but also a reader named Brad, encountered a peculiar issue while using Firefox 3 to access We were both greeted with an “unsupported browser” notification, despite knowing that Firefox 3 should seamlessly work with MobileMe. A colleague from TUAW confirmed that the site functions correctly on their end.

After some digging, Brad and I discovered a shared culprit in our setups: the Ubiquity plugin.

The root of the issue lies in the user-agent string used by MobileMe to identify the browser. Normally, without Ubiquity, the string appears as Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv: Gecko/2008120121 Firefox/3.0.5. However, with Ubiquity, it changes to Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv: Gecko/2008120121 Firefox/3.0.5 Ubiquity/0.1.5.

This additional ‘Ubiquity/0.1.5’ text confuses MobileMe, leading it to misidentify the browser as unsupported.

Fortunately, there’s a straightforward fix for this, as outlined by Tim Jarrett on his blog, which allows continued use of both Ubiquity and MobileMe. You can learn more about this solution here.

Special thanks to Brad for his collaboration!

Here’s how you can adjust your Firefox settings:

  1. Type about:config in the address bar.

  2. Confirm your intent by clicking “I’ll be careful, I promise”.

  3. Enter ubiquity in the search box.

  4. Locate and double-click general.useragent.extra.ubiquity.

  5. Clear the text box when prompted and confirm by clicking OK.

  6. Close the configuration tab.

After making these adjustments, try accessing again. You should be able to reach the login screen without encountering the “unsupported browser” error.

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Tj Luoma

Gary is a dedicated writer for TUAW, bringing a wealth of knowledge and enthusiasm for all things Apple. With a keen eye for detail, Gary covers everything from the latest iPhone and iPad releases to in-depth reviews of the MacBook Pro and Apple Watch. His insightful articles help readers navigate the ever-evolving world of Apple technology. Gary’s expertise and clear writing make him a trusted voice in the Apple community.