Hi Ed,
The software as a whole is compatible with V5.2, however like another well known addon, P/atc suffers from the same problem within P3d which is the use of HTML menus.
LM have said they will address with the release of a 'hotfix' so at the moment you would be lucky to complete a flight of any length using P/atc.
There is a workaround, of sorts, to force the use of scaler menus.
I don't think any of this is due to any incompatibilitys within P/atc though.
Cheers,