If you're running 64-bit PC-DMIS, you need to update to 2015 SP3 (or upgrade to 2015.1 SP1 or later). Temporary solution for 2015 R is to run the 32-bit version instead.
Bug report PCD-88020 "Program flow no more works in PCDMIS x64 basic script" is marked as fixed for those later versions.
If you're running 64-bit PC-DMIS, you need to update to 2015 SP3 (or upgrade to 2015.1 SP1 or later). Temporary solution for 2015 R is to run the 32-bit version instead.
Bug report PCD-88020 "Program flow no more works in PCDMIS x64 basic script" is marked as fixed for those later versions.