I was flying BOS to IAD today and while programming the FMC for a SID I got a "Program Pin Error".  The FMC remained operational except I could no longer choose any SIDs or STARs, the only option was FMC  <Act> displayed.  I never had any issues in FSX's version of the 737 but I recently switched to P3D and its the first time I've seen this.  Did I miss a step or is this a bug?

Not a known bug.  That error message is usually caused by the program that runs the FMS when it runs into an error. Nice that it does that instead of leading to a CTD.  I don't think your issue is FSX vs P3D (I use P3D for all personal use).  The problem may be with the flightplan file if that was imported.  I have flown the BOS to IAD trip using HYPER5 no problem so it's probably not that either.

 

I wouldn't think you'd need to import a flightplan for such a route, basically a departure direct to an arrival. What was your situation?

I was using ProATCX.  Never had an issue when I was using the FSX version, did a dozen or so flights before switching to P3D.  Nearly every flight I have a program pin error now.

I am able to duplicate this anytime with any flight plan it seems.  After I activate my FP and click a departure I get the error.

 

 

Nearly every flight I have a program pin error now.

 

Please submit a trouble ticket at support.precisionmanuals.com, the PMDG Product Support portal.  Support has separate accounts from sales, expect to create a new account there to open a ticket.