I wanted to add the Chartmaker extension but every time I try to load it my Firefox crashes when I click the "Import" button, I never even get a file picker. System is Win7 Pro X64, FF is whatever's most current, I literally JUST updated 12 minutes before this. Repeatable crash afaik, I've done this several times in a row now. Chrome (whatevers most current) worked fine to import the extension, and I left the project open in the failed to import Firefox window and just reloaded it after using Chrome and everything seems to be fine, I could add the components and everything looks alright (using the new blocks is another thing but beyond the scope here.)
I have a copypasta of the FF bug report if that'll help out, not allowed to include the text here, new user link limit.