Game crashes when you try to connect to a server with the launcher if you have an AMD GPU.

Settings → Compatibility, set GLSL Support to Disabled.

Game crashes stating it there is an invalid value with the resolution setting. (NOTE: This happened on Linux for me with an NVIDIA GTX970.)

This is an issue with OpenGL. Edit WurmLauncher/PlayerFiles/configs/default/gamesettings.ini and set glsl_enabled=2.