The new starter service results in a compile error at my existing B4A5.02 sourcecode.
At least I think so
Compiling in B4A5.02 version completes without an error.
After filling this bug-report, I realized that my current version is 5.02. The new beta is 5.20.
I think I missed some previous updates and maybe this causes that error.
Maybe the update step form .02 to .20 is to big.
It seems like you are referencing the wrong Core.jar library (from the previous version). Try to reinstall v5.20 in a new folder (c:\B4A) and see whether it works or not.