Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.2a1pre) Gecko/20090619 Minefield/3.6a1pre After I copied my files to my new laptop, everything worked except for my extensions in Firefox. They were listed in my Add-ons window, but they didn't work; I got errors like this: Couldn't convert chrome URL: chrome://greasemonkey/content/icon_medium.png Deleting my extensions.cache fixed it. Rob Strong suspects this happened because one of my extensions was "installed" using the text file method, and extensions.cache stored a persistentDescriptor, which on Mac is a hard-disk-specific blob rather than an absolute path. My old extensions.cache had this line: app-profile firstname.lastname@example.org abs%AAAAAAFiAAIAAQxNYWNpbnRvc2ggSEQAAAAAAAAAAAAAAAAAAADBcRzJSCsAAAAH2LQMY3Jhc2h0ZXN0aWZ5AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABST+ycVnNkYAAAAAAAAAAP////8AAAkgAAAAAAAAAAAAAAAAAAAACWpydWRlcm1hbgAAEAAIAADBcY1JAAAAEQAIAADFZ6bGAAAAAQAIAAfYtAAAbxkAAgApTWFjaW50b3NoIEhEOlVzZXJzOmpydWRlcm1hbjpjcmFzaHRlc3RpZnkAAA4AGgAMAGMAcgBhAHMAaAB0AGUAcwB0AGkAZgB5AA8AGgAMAE0AYQBjAGkAbgB0AG8AcwBoACAASABEABIAHFVzZXJzL2pydWRlcm1hbi9jcmFzaHRlc3RpZnkAEwABLwAAFQACABD//wAA 1245394758 Re-generated on new computer after I moved the old extensions.cache, and now works: app-profile email@example.com abs%AAAAAAFiAAIAAQxNYWNpbnRvc2ggSEQAAAAAAAAAAAAAAAAAAADGXsV3SCsAAAAKtSYMY3Jhc2h0ZXN0aWZ5AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABYWE8VnNkYAAAAAAAAAAP////8AAAkgAAAAAAAAAAAAAAAAAAAACWpydWRlcm1hbgAAEAAIAADGXyfnAAAAEQAIAADFZ6bGAAAAAQAIAAq1JgAKD8YAAgApTWFjaW50b3NoIEhEOlVzZXJzOmpydWRlcm1hbjpjcmFzaHRlc3RpZnkAAA4AGgAMAGMAcgBhAHMAaAB0AGUAcwB0AGkAZgB5AA8AGgAMAE0AYQBjAGkAbgB0AG8AcwBoACAASABEABIAHFVzZXJzL2pydWRlcm1hbi9jcmFzaHRlc3RpZnkAEwABLwAAFQACABD//wAA 1245394758 I think multiple things went wrong here. Firefox cached the information about the file at too low a level, and then didn't recover (e.g. by at least letting my *other* extensions work) when it discovered that information was incorrect.
This is potentially related to bug 344671. If you had the extensions.cache and extensions.ini pre- and post- to attach then it would be useful.
The extensions.ini was empty
I can report getting this problem too. It happened when dual-booting between two Linux distros or after adding/removing/updating Firefox versions. I think the latter. The problem is that often no extensions would be active. Nothing on the UI and they wouldn't work (Greasemonkey) either. Removing extensions.cache would fix the problem.
Created attachment 400338 [details] extensions.cache causing the problem Uploading extensions.cache which causes the problem.
We now use normal paths in extensions.ini so I think this should be fixed