I haven't been able to figure this out. Since I've upgraded to P3D v2.3, I have not been able to use FSUIPC. When I use any version of FSUIPC, Prepar3D would load up to "100% complete!" and then promptly crash with the window "Prepar3D has stopped working". I've checked the Windows event viewer logs and it always traces back to MSVCR100.dll. I had hoped that upgrading to P3D v2.4 would solve the problem, but it remains. I've used different MSVCR100.dll files, started with clean Prepar3D.cfg and scenery.cfg files, but no luck. When I remove FSUIPC.dll, P3D loads up without any problem. FSUIPC has worked fine with my previous versions of P3D with all the addons, and it still works fine with FSX, which is still on my machine. Any ideas anyone? Here's a copy of the Windows event log...
Prepar3D.exe 2.4.11570.0 542314d3 MSVCR100.dll 10.0.40219.332 4e1a9f56 c0000417 0008af3e 158c 01cfe3f5b987c601 I:\Lockheed Martin\Prepar3D v2\Prepar3D.exe C:\WINDOWS\SYSTEM32\MSVCR100.dll c98def37-4fea-11e4-be8b-74d4359c69ce