Well, i've got the same pb here.... very weird.
After updating Corona on v3 hf1 on my WS on W10, no pb, but when updating the other one on W7, same error as Yanosh and I got it working.
BUT, the DR is still in v3 and not tne v3 hotfix 1... even when executing the DRserver.exe from the folder, it stays under v3....
Any idea ?
Thx