Sigil: City of Doors

Hello!

Make sure that you add the files when the game is not running. You might want to also clear out any stray lzma files which may be confusing the autodownloader.

I am having this same issue, but when I try to change the LZMA file to the proper .trx file, it insists on downloading the LZMA, even after deleting it.

LZMA is just the compressed format. If it does not download properly, then it usually won't extract (which is what the autodownloader is complaining about).

Just download the files linked above and you should be good to go.