Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

This thread was archived. Please ask a new question if you need help.

Upgraded to El Capitan OS X and now T-bird will not launch. Message: A copy of Thunderbird is already open. Only one copy of Thunderbird can be open at a time."

  • 1 reply
  • 1 has this problem
  • 1 view
  • Last reply by christ1

Jman88
Jman88
more options

Yesterday I upgraded from Moutain Lion to El Capitan on my MacBook.

Previously Thunderbird worked fine. Now it will not launch and I get an error message that "A copy of Thunderbird is already open. Only one copy of Thunderbird can be open at a time." Unfortunately there is no other copies of Thunderbird running. If I look in the "Force Quit" window I don't see Thunderbird.

I tried deleting and re-installing Thunderbird with latest version. I still get the same message.

Firefox works fine. Can anyone help? Thanks!

Yesterday I upgraded from Moutain Lion to El Capitan on my MacBook. Previously Thunderbird worked fine. Now it will not launch and I get an error message that "A copy of Thunderbird is already open. Only one copy of Thunderbird can be open at a time." Unfortunately there is no other copies of Thunderbird running. If I look in the "Force Quit" window I don't see Thunderbird. I tried deleting and re-installing Thunderbird with latest version. I still get the same message. Firefox works fine. Can anyone help? Thanks!

All Replies (1)

christ1
christ1
  • Top 25 Contributor
more options

http://kb.mozillazine.org/Profile_in_use