1.4.1 Ubuntu "Rebuilding All Screens" forever - unable to open existing project

Unable to open a project from 1.3.4 release in 1.4.1 under Ubuntu 24.04 x64

Tried several times to close app and to running it again

Opening a project from the previous release 1.3.4
freezes the application while trying “Rebuilding All Screens”.

Stepping back to 1.3.4 works fine.

Is there a migration tool needed? Or can I modify something
in the project file with a text editor?

Thank you.