pol2095 Thank you!
So, building with 50.2.2.6 results with correct build which is detected as "executable" by Ubuntu and can be run with double-click from GUI and does not cause the crash.
Building with 50.2.3.1 results with a build which is detected as shared library (application/x-sharedlib), after double-click in the Ubuntu GUI it doesn't run by itself but asks for the associated app, and if run from the Terminal it crashes after the preloader.
I'll use 50.2.2.6 for now, will update my games for Linux soon.