Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

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

Only one copy of Firefox can be open at a time

Olá!

Ontem, quando reiniciei o Firefox, apareceu-me esta mensagem de erro: "Close Firefox. A copy of Firefox is already open. Only one copy of Firefox can be open at a time."

Entretanto desinstalei o Firefox, removendo da pasta de Aplicações.

Acontece que agora nem me deixa voltar a instalar, aparecendo sempre a mesma mensagem de erro.

Percebo muito pouco de Mac, daí que agradeça ajuda!

Olá! Ontem, quando reiniciei o Firefox, apareceu-me esta mensagem de erro: "Close Firefox. A copy of Firefox is already open. Only one copy of Firefox can be open at a time." Entretanto desinstalei o Firefox, removendo da pasta de Aplicações. Acontece que agora nem me deixa voltar a instalar, aparecendo sempre a mesma mensagem de erro. Percebo muito pouco de Mac, daí que agradeça ajuda!

All Replies (2)

Probably you have Profile locked in your Profile folder

see Remove the profile lock file ".parentlock" (Mac OS X)


thank you

Please mark "Solved" the answer that really solve the problem, to help others with a similar problem.

Thanks for the help!

Anyway, this didn't solve the problem. The problem is I couldn't find my profile folder in Firefox since i've uninstalled it.

By the way, I've solved the problem yet.

Searching in Google about how to completely uninstall applications on mac, I've found AppZapper.

I really don't like this kind of apps, but the thing is, the problem is solved, completely!

Thanks anyway!