User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1) Gecko/20090615 Firefox/3.5 (.NET CLR 3.5.30729) Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1) Gecko/20090615 Firefox/3.5 (.NET CLR 3.5.30729) You cannot use or install any addons for any of the firefox builds; the beta or 3.11. I have tried both to no success. Any addons i had in stalled are rendered useless; they say they're installed but they dont work (this goes for any themes as well). This is the exact error that occurs when trying to install chromifox companion on 3.5RC Firefox could not install the file at https://addons.mozilla.org/en-US/firefox/downloads/latest/10339/addon-10339-latest.xpi because: Unexpected installation error Review the Error Console log for more details. -203 All other addons produce similar errors as well. Reproducible: Always Steps to Reproduce: 1.Open Firefox Actual Results: No addons were displayed properly (themes etc.) Or a failed installation Expected Results: Addons should do what they're designed to do or they should be installed without error.
[BUmping version - still in 3.6 according to duplicates]
Is this still a problem in more recent versions of Firefox?
(In reply to Dave Townsend (:Mossop) from comment #5) > Is this still a problem in more recent versions of Firefox? I haven't seen it in a long time.
Since we rewrote the entire add-ons manager and I don't think it is even physically possible to get such an error message any more I don't think we need to keep this bug open any longer.