Studio 15.0b3 fails license check.

On iMac running OS 10.13.4
Went from Studio 14.3 (running just fine, thank you very much) to 15.0b3.
App launched once just fine.
Second launch failed. Subsequent retries all fail.
Went back to 14.3. Launches and asks for activation code, which when entered allows app to start.
Tried 15.0b3 again. Exits at Checking Licenses.
reinstall 14.3: it's fine.
Installed 15.0b2, it asks for activation code. It's working fine.

A fun couple of hours of trial and error. Open for suggestions.

Same software installs and works correctly on the MBP laptop. I'll keep it on there for now because it updates the project database, which is not backwardly compatible to v14. Too much in progress on 14 right now to switch everything to a beta version. I'll just attach the extra 27" monitor and external Thunderbolt drives to the laptop for the test projects.