Okay, it looks like you have a couple of issues here, so please do the following.
1. Find the file named PF3_Register.exe from the main PF3 folder. Right-click on it and select 'Run as Administrator'. Wait 30 seconds then try loading your flight plan again.
2. If you still have the same problem please zip and send me all the files in your PF3\Flight\FPP folder
3. Rebuild the PF3 database, including running MakeRwys (This should eradicate the first error you receive when selecting 'load a flight plan'