Where did you install Firefox from? Help Mozilla uncover 3rd party websites that offer problematic Firefox installation by taking part in our campaign. There will be swag, and you'll be featured in our blog if you manage to report at least 10 valid reports!

Avatar for Username

Sykje yn Support

Mij stipescams. Wy sille jo nea freegje in telefoannûmer te beljen, der in sms nei ta te stjoeren of persoanlike gegevens te dielen. Meld fertochte aktiviteit mei de opsje ‘Misbrûk melde’.

Learn More

Dizze konversaasje is argivearre. Stel in nije fraach as jo help nedich hawwe.

Every time I try to start Firefox I get"A copy of FF is already open. Only one can be opened at a time" How o I get FF to work?

  • 1 antwurd
  • 4 hawwe dit probleem
  • 9 werjeftes
  • Lêste antwurd fan TonyE

theappletreeusa
theappletreeusa
more options

I can't get Firefox to start up. I've downloaded a new copy several times and keep getting the error message, "A copy of Firefox is already open. Only one copy of Firefox can be open at a time". I do not have Firefox running anywhere.

I can't get Firefox to start up. I've downloaded a new copy several times and keep getting the error message, "A copy of Firefox is already open. Only one copy of Firefox can be open at a time". I do not have Firefox running anywhere.

Alle antwurden (1)

TonyE
TonyE
  • Moderator
more options

See "Firefox is already running but is not responding" error - How to fix, the image shown in that article is the Windows equivalent of the error message that you are receiving, but the information relates to the Mac.