Programming Languages, Martials Arts and Computers. The Weblog of Chris Double.
Firefox extensions check what version of Firefox they run on and sometimes don't run if you are running a newer version of Firefox due to failing the check.
When running development builds of Firefox it's sometimes useful to be able to use these extensions. You can force then extension version check to be ignored by adding the configuration option 'extensions.checkCompatibility' set to 'false'.
This option can be added by going to the URL 'about:config'. Right click on the list and choose 'New', followed by 'Boolean'. Enter the name as 'extensions.checkCompatibility' and the value as 'false'.
Once done extensions will no longer check to see if they are compatible with the verson of Firefox you are running. You can remove the preference or set it to 'true' to enable the check again.
This will only work with Firefox 2 and above as that was when the option was added. It is documented at this Mozilla page.