F2063: could not compile used unit 'MyAccess'

F2063: could not compile used unit 'MyAccess'

I'm using the new MyDAC 12.0 professioal in Delphi 12.0. I get this error. The same for the unit 'DbAccess'.
This version of MyDAC in Delphi 11.3 works fine.
Is something wrong with the paths? Incompatible .dcu ?