The program executes a VB program using a call to C$SYSTEM. This works fine when running directly on Windows, but when run via Thin Client the program does not execute.
The C$SYTEM library routine accepts a "flags" value. The various flags are described in the page for C$SYSTEM in Appendix I of the AcuCOBOL-GT documentation.
There we see a flag named CSYS-DESKTOP with a value of 128. This flag tells the Runtime to execute the command on the client PC when running in a Thin Client environment. This flag value is ignored if not running via Thin Client.
The solution is to add the CSYS-DESKTOP value to whatever flag value is already being used.