Server Error

Yesterday and today when I click on “Calculate” I get a “server error” message. Any suggestions?

I think this is an NCM bug. I looked at our error logs and found a couple instances where Stockfish would crash because it’s given a FEN position with castling “KQkq” (all castling options available) but without the corresponding pieces in the correct position to castle.

When Stockfish gets this, it (correctly, I think) crashes triggering the “server error” message you’re seeing.

NCM is supposed to be checking for this and un-setting castling options when they’re impossible after FEN is pasted.

I’ll push a fix today!

In the meantime, you should be able to simply move a piece on the board and move it back to have NCM automatically disable impossible castling options.

Thank you for the quick response.

Fix pushed. Now, when pasting FEN, the website automatically strips invalid castling options. Thank you for reporting this!

Tested on several positions, and everything seems good. Thanks for the fix.