In this SUMO Contributors forum thread [http://support.mozilla.com/en-US/forum/3/518327?] we discussed breaking the instructions for troubleshooting multiple versions of Flash from the main ((Using the Flash plugin with Firefox)) [http://support.mozilla.com/en-US/kb/Using+the+Flash+plugin+with+Firefox] article. This bug is for making that. In the thread we outlined the contents of the article.
Marking the draft as FIXED. For Windows and Mac, we recommend using Adobe's uninstaller. If it doesn't work, we recommend finding the plugin paths and removing old versions. For Linux, we skip straight to removing the old versions, as Adobe does not have an uninstaller. The forum thread linked above has more discussion.
It looks good to me. Does Chris (or another admin) need to review and approve the article, to move it to the KB?
Are there more specific symptoms than "does not work properly"?
Biggest issue is certain Flash content not working when other content does. i.e. if you have a version conflict and visit a Flash object that needs a higher version, that won't work.
Is this article still needed? See https://support.mozilla.com/en-US/forums/contributors/568624
Moved to KB.
(For the record) The old topic at https://support.mozilla.com/en-US/forums/contributors/568624 was apparently moved from the contributors forum to the KB articles forum and is now at https://support.mozilla.com/en-US/forums/knowledge-base-articles/568624 (the old link no longer works!)