Funkcionalnosć toś togo sedła se pśez wótwardowańske źěła wobgranicujo, kótarež maju wašo dožywjenje pólěpšyś. Jolic nastawk waš problem njerozwězujo a cośo pšašanje stajiś, wobrośćo se na našo zgromoźeństwo pomocy, kótarež na to caka, wam na @FirefoxSupport na Twitter a /r/firefox na Reddit pomagaś.

Avatar for Username

Pomoc pśepytaś

Glědajśo se wobšudy pomocy. Njenapominajomy was nigda, telefonowy numer zawołaś, SMS pósłaś abo wósobinske informacije pśeraźiś. Pšosym dajśo suspektnu aktiwitu z pomocu nastajenja „Znjewužywanje k wěsći daś“ k wěsći.

Dalšne informacije

Toś ta nitka jo se archiwěrowała. Pšosym stajśo nowe pšašanje, joli trjebaśo pomoc.

After downloading and starting Firefox, I get an error message that says "A copy of Firefox is already open. only one copy of Firefox can be open at a time." The thing is I don't have another copy open.

  • 4 wótegrona
  • 1 ma toś ten problem
  • 55 naglědow
  • Slědne wótegrono wót aurolyn2

krich377
krich377
more options

After downloading and starting Firefox, I get an error message that says "A copy of Firefox is already open. only one copy of Firefox can be open at a time." The thing is I don't have another copy running.

After downloading and starting Firefox, I get an error message that says "A copy of Firefox is already open. only one copy of Firefox can be open at a time." The thing is I don't have another copy running.
Pśipowjesone fota wobrazowki

Wubrane rozwězanje

Does Firefox appear in the App Switcher? If you hold down the Command key and then press and release the Tab key, MacOS should display a bar of running programs that you can switch to by pressing Tab additional times. Is Firefox listed?

If Firefox is listed, if you keep the Command key pressed and press Tab enough times to select it, and then release both the Tab and Command keys, in theory, Firefox should be made the active application.

Does anything appear to happen on the screen?

If not, is there any possibility that Firefox is open on a different display? Obviously only applicable if you use (or have used) multiple displays.

Toś to wótegrono w konteksće cytaś 👍 1

Wšykne wótegrona (4)

jscher2000 - Support Volunteer
jscher2000 - Support Volunteer
  • Top 10 Contributor
more options

Wubrane rozwězanje

Does Firefox appear in the App Switcher? If you hold down the Command key and then press and release the Tab key, MacOS should display a bar of running programs that you can switch to by pressing Tab additional times. Is Firefox listed?

If Firefox is listed, if you keep the Command key pressed and press Tab enough times to select it, and then release both the Tab and Command keys, in theory, Firefox should be made the active application.

Does anything appear to happen on the screen?

If not, is there any possibility that Firefox is open on a different display? Obviously only applicable if you use (or have used) multiple displays.

krich377
krich377 Pšašaŕ
more options

I finally just reinstalled Firefox, and things seem to have stabilized. Thanks for the tip on the running programs!

Émile Jetzer
Émile Jetzer
more options

I have had the same problem appear twice, and found the linked solution to work in both cases: https://osxdaily.com/2010/05/16/fix-for-close-firefox-a-copy-of-firefox-is-already-open-error/

Doesn't require a reinstall, but basic knowledge of Terminal and Mac OS file structure.

aurolyn2
aurolyn2
more options

I have this same problem -- Firefox is not running in the app switcher (or on another display), and I tried deleting and re-installing it. Tried going into the Terminal to run Emile's solution but i don't really know enough to make it work. Any other suggestions?