Hi,
There is a well-known workaround for older airplanes that require the simulator to be run as a process named fsx.exe. Namely, making a copy of Prepar3D.exe -> fsx.exe and Prepar3D.cfg -> fsx.cfg, and starting the sim from that fsx.exe.
Previously, before v2.5 hotfixes, FSUIPC played along nicely, but now seems to crash as soon as the sim starts.
Here's the log:
1154 System time = 12/06/2015 23:04:52
1154 FLT path = "C:\Users\....\Documents\Prepar3D v2 Files\"
1217 Trying to connect to SimConnect Acc/SP2 Oct07 ...
1217 FS path = "C:\Program Files (x86)\Lockheed Martin\Prepar3D v2\"
1591 LogOptions=00000000 00000001
1591 Failed to find CONTROLS timer memory location!
1591 ### Failed to obtain SIM1 Frictions access: no frictions facilities available!
1591 Reason 6: SIM1 base=00C60000
1591 FrictionAddr=00C62870 contains CCCC0004
1591 BrakingAddr=00C63B30 contains A0EC8150
1591 Hook Error: no DOS signature for SIM1.dll
1591 Hook Error: no DOS signature for VISUALFX.dll
Even if the fsx.exe is not patched to change version information, but is kept an identical copy of Prepar3D.exe, these crashes don't go away. AssumeP3Dversion setting doesn't seem to make any difference either.