"SYSMSG" was used as the name for an IO field, and "YES" or "SYSMSG"
was specified in the SYSMSG field.
Restriction: This topic applies only when the AppMaster Builder AddPack has been installed, and applies only to Windows platforms.
Resolution:
Either change the name of the IO field and supply that name for
SYSMSG, or delete the IO field and allow the SYSMSG parameter to build the IO
field upon screen generation. See Creating System Message Fields.