Compiler failed assertion for 2019r2

I’m getting odd crashes “Compiler failed assertion” when running projects the first time in Xojo 2019r2. Today I updated Open Lingua and got: 57864 - Compiler failed assertion at LinkLD.cpp:394

Just now I tried to run the Kaju Admin app and got: 57866 - Compiler failed assertion at MachineCodeLinker.cpp:83

A couple of days ago I made: 57739 - Compiler failed assertion at MachineCodeLinker.cpp:83

All three aren’t reproducible. But as Shakespeare said “three is a crowd”. I don’t remember getting such errors before.

More tips are needed. Which OS?

2times High Sierra and once Catalina I think.