Download Firefox - 12-51 52 Esr 'link'

: Before installing an older version over a newer one, back up your profile data to prevent data loss or corruption.

: Firefox 52 ESR was the last version to support non-Flash NPAPI plugins. Versions 51 and below are often sought by users who need to maintain access to legacy web-based tools or hardware (like old webcams) that rely on these plugins. Legacy Extensions Download Firefox 12-51 52 Esr