URControl: Unknown Mutex::Mutex() calling exit (-1)

Hello everyone,

I’ve installed URSim (I’ve tried both the latest 5.XX and 3…XX) on Ubuntu 20.04 LTS (not a fresh install) and the program starts but on the Initialisation Screen it says NO CONTROLLER.
When running ./starturcontrol.sh, nothing changes and when running ./URControl directly, it displays

Unknown Mutex::Mutex() calling exit (-1)

I have installed URSim on a fresh install before and it worked after running ./starturcontrol.sh.

Does anyone know what this error means? Looking for it online doesn’t give many results.