Please advise

[danispringer]

If this is expected behavior, totally fine, just wondering if it is. Thank you.

official-stockfish/Stockfish#4549

[daylen]

So, the app doesn't crash if you copy the FEN to your clipboard and use Edit > Paste FEN. I agree it shouldn't crash on reading a PGN file either… but I probably didn't pipe the same validation logic through that. Alas!

[danispringer]

Nothing to do with edit vs pgn. issue occurs if position is illegal (e.g.: >10 rooks per color), if NNUE is ON.

[chromi]

As a workaround for a known limitation of the NNUE evaluator, perhaps disable NNUE for types of positions it's known to be unable to handle. That would at least stop the engine from crashing.