Brave wont open

Forpli · September 1, 2025, 9:37am

Did you change the hostname of your pc? This can cause this error.

I'm not sure - you could try this:

Close brave and delete

SingletonSocket
SingletonLock
SingletonCookie

https://www.reddit.com/r/brave_browser/comments/1am8pod/brave_wont_open_on_ubuntu/

You could search it there (I'm not at the computer in the moment, so can not check it):

~/.config/BraveSoftware/Brave-Browser/SingletonLock

github.com/brave/brave-browser

Improve Linux "SingletonLock" error message to include solution

opened 11:59PM - 19 Nov 24 UTC

Brave-Matt

suggestion OS/Linux priority/P5 OS/Desktop

### Description Linux will throw an error message when a profile or other proce…ss attempting to be used is already in use. For example, one such user sees the following error message when attempting to change the network hostname: ``` [71346:71346:1117/150207.094641:ERROR:process_singleton_posix.cc(358)] The profile appears to be in use by another Brave process (2200756) on another computer (<old_hostname>). Brave has locked the profile so that it doesn't get corrupted. If you are sure no other processes are using this profile, you can unlock the profile and relaunch Brave. [71346:71346:1117/150207.094778:ERROR:message_box_dialog.cc(190)] Unable to show message box: Brave - The profile appears to be in use by another Brave process (2200756) on another computer (<old_hostname). Brave has locked the profile so that it doesn't get corrupted. If you are sure no other processes are using this profile, you can unlock the profile and relaunch Brave. ❯ hostname <a_different_hostname> ``` The solution to this issue/message is to remove `SingletonLock` from `.config`: ``` rm ~/.config/BraveSoftware/Brave-Browser/SingletonLock/SingletonLock ``` As it may take more time than it is worth to auto-detect this situation when it occurs (cc @fmarier on this), it may be helpful to improve the error messaging to include the cause of the error and the command to fix it. ### Steps to reproduce 1. See description ### Actual result Error message is shown without denoting the cause of the error ### Expected result Error message should be updated to include the cause and (potentially) the command to run to remove `SingletonLock` so that users know where to look. ### Reproduces how often Easily reproduced ### Brave version (brave://version info) All ### Channel information - [x] release (stable) - [x] beta - [x] nightly ### Reproducibility - [ ] with Brave Shields disabled - [ ] with Brave Rewards disabled - [ ] in the latest version of Chrome ### Miscellaneous information Original user post: https://community.brave.com/t/brave-profile-locked-after-changing-network-hostname-on-linux/581533