I'm getting the subject error on the attached flight plan, which came directly from SimBrief. I've never had this error before, nor does it seem to occur on any other plan - only this one. Further, I tried several different ways of creating flight plans between these two airports and all failed. Ended up doing the flight without ATC which was somewhat surreal...
Also attaching PF3.ini and FPP files. Any ideas what the problem could be?
It does let me do edits, and then says "There was a problem and your changes have NOT been saved! 55-100". However, it does seem to save, but won't ever let me connect to the sim.