Yes, we release an important version this week-end that slightly changes the preprocessor behaviour.
Even if this should have no impact on most diagrams, some might be impacted, especially when doing high usage of the preprocessor :-)
It's difficult to solve your issue without having your full diagram, but I think you should now use:
!unquoted function DRAW($x) return %set_variable_value($x, 1)
'====DRAW Specific Diagrams by Comment/Uncommenting Line===
'====Only uncomment one line at a Time======================
Alice -> Bob : part1
Alice -> Bob : part2
Alice -> Bob : part3
Usually, we try to respect ascending compatibility. In this case, it was not possible to have a full compatibility.
But we gain a much more powerful preprocessor
Hope this helps!