Let me see if I understand you correctly.
You can start PF3 and load a flight plan? Then, when you hit the 'Connect' button PF3 errors? Does it give any message at all?
Please recreate the problem and then send me all the logs from your PF3/Logs folder.
Yes, PF3 works with P3D 64 bit, provided you are using the correct version of FSUIPC.
You might also like to try downloading and installing the latest cumulative updates package from the forum.
...incredible, I tried PF3 one more time to send you the logs you asked me again, logically it should have been the same as the ones I sent you because yes, you understood, I could start PF3, load an FP, go through all the menus without any problem. But as soon as I pushed the "Connect to FS" button, Blam, PF3 encountered a problem and must close (Windows message) with in the Event Viewer the report:
Faulting application name: PF3.exe, version: 126.96.36.199, time stamp: 0x5bb1f704
Faulting module name: clr.dll, version: 4.7.3260.0, time stamp: 0x5bb7bcb7
Exception code: 0xc0000005
Fault offset: 0x004550dd
Faulting process id: 0x67c
Faulting application start time: 0x01d49f8444bc58e5
Faulting application path: C:\FS_Addons\PF3\PF3.exe
Faulting module path: C:\Windows\Microsoft.NET\Framework\v4.0.30319\clr.dll
Report Id: a056d3bf-0b77-11e9-bf2b-240a640748f4
So I relaunch PF3 for the umpteenth time and to my great surprise, it works as before.
I had tested with and without Active Sky, MCE and so on...and I still had this crash. I even had before you asked, reinstalled the latest cumulative updates package!
Now the most curious thing is that as a result my logs are no longer empty, they seem to have returned to the way they were before!
Sorry for the inconvenience, everything seems fine now (fingers crossed)
Thanks and Regards,