[#23915](https://trac.torproject.org/projects/tor/ticket/23915) suppresses the multithreading error. ([diff](https://trac.torproject.org/projects/tor/wiki/doc/TorBrowser/Sandbox/Linux?action=diff&version=29)) URL: https://trac.torproject.org/projects/tor/wiki/doc/TorBrowser/Sandbox/Linux?version=29