Whenever a new version of Firefox releases, FDM Plugin installed by Free Download Manager will be automatically disabled in the Mozilla browser. The rapid release cycle not helping FDM plugin to compatible with the newly released Firefox versions, till now, but, whenever new versions of Firefox are released, geek users able to edit install.rdf file to make Free Download Manager plugin work in Firefox again.
Hope no more workarounds like these needed in future for FDM users as Mozilla has finally reviewed FDM plugin and is now available for download in AMO. So from now onwards, Firefox may not disable FDM plugin, since it has been approved and supports up to version 18, and Firefox takes the care of auto updating this add-on.
Update September 23, 2014: The add-on has been removed by Mozilla, because it has violated their add-on rules in AMO, as the page now showing a message ‘This add-on has been disabled by an administrator’. We’ll let you know more soon about this.
Read: FDM 5.0 Alpha review
Free Download Manager Plugin for Firefox now available on AMO
If you’re using FDM 3.9 build 1249 on your computer, then Firefox might have disabled the FDM plugin for you, remove that plugin and download and install the latest plugin with version number 18.104.22.168 from AMO here.