#define KACF_FTMFROMCURRENTAPT 0x00000020
This application compatibility flag used to be documented in early Windows 10 EWDK.
If set, a DCOM Free-Threaded-Marshaled Object has its' stub parked in the apartment that the object is marshaled from instead of the Neutral-Apartment. Having to set this bit indicates a busted App that is not following the rules for FTM objects. The app probably has other subtle problems that NT 4 or Win9x didn't show. Blindly using the ATL wizard to enable using the FTM is usually the source of the bug.