For some reason, the formatting of the chess.com website changes depending on whether or not this extension is loaded.
Specifically, the move number has been moved to the right side of the move list, so that moves are now formatted as:
d4 d5 1
c4 Nc6 2
etc

As a result, the extension no longer provides move suggestions, in either Standard or FEN mode.
I have tested the chess-cheats.zip contents in both Chrome and Firefox.
With the extension loaded, the fonts and formatting on chess.com change. Everything becomes centered instead of left-justified (which is probably why the move number moved to the wrong side of the move list).
When you remove the extension, the chess.com website loads normally.
If you disable the extension, then reload the page, the page will load normally. And then if you enable the extension while the page is still open, it will immediately change formatting and center all the text. Disabling the extension again after this does not change the page, until you refresh.

This is a good attempt, but the project sources are in need to attention. Specifically there seems to be defunct code in almost all the ts source codes. Please make an effort to clean up and update. This has a lot of unexploited potential.

I just get this error whenever i press start hack
I'm using mozilla and this happened after i updated the extension

I can't see the arrows. Do you have the same error?

Would it be possible to make this great addon compatible with Lichess? That would be really cool.

Please fix the bug no longer showing arrows