[MCL-14214] Launcher not starting on Ubuntu 20.04

Possible Fix

This issue seems to happen to AMD Ryzen 3rd geneneration CPU:s in combination with Linux. See Ars Technica article for more info about the issue. Performing a BIOS update should repair your system.

AMD Drivers and Support

After recently upgrading to Ubuntu 20.04, the existing installation worked fine. However, after upgrading the launcher to the latest version today, starting the launcher pins one CPU core to 100% utilisation indefinitely, and the interface does not show up.

The launcher log looks consistently the same, with the final line being:

LauncherController.cpp(165)] Constructing launcher controller with workDir: .../.minecraft, isActive: 1

Running the launcher from the terminal with sudo does not fix the problem.