User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_8; en-us) AppleWebKit/533.21.1 (KHTML, like Gecko) Version/5.0.5 Safari/533.21.1
Build Identifier: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:5.0) Gecko/20100101 Firefox/5.0
Starting with Firefox 5.0, binary XPCOM components must have exactly the correct Module::kVersion or they will not load. Since this will happen with any extension containing such a component that has not been updated recently, this should not be a silent failure. There should be at least a warning printed to the system stderr or Firefox' Error Console
Steps to Reproduce:
1. Install an older Firefox extension containing a Binary XPCOM Component into Firefox 5.
2. Launch Firefox 5 and do whatever is needed to load the extension.
Error console prints only a warning saying that the XPCOM Component is undefined.
Error console, and probably system's stderr, should instead print a warning explaining that there was a mismatch in Module::kVersion, giving the required kVersion and the found kVersion, with a recovery suggestion to update the extension and a link to the documentation further explaining the issue.
For more information, see this bug
Created attachment 541725 [details] [diff] [review]
Console message for kVersion mismatch, rev. 1