Failure to minify valid css

[Kile-Asmussen]

When attempting to minify the following file, I get the error Invalid block at line 205:26

https://github.com/Kile-Asmussen/proxy_mtg/blob/929b78887dc91031787ab4690caa7dd29c455349/css/font-settings.css

As far as I can tell, the file is completely valid CSS, according to VSCode and firefox. I can't seem to replicate the error in a minimal example.

[Kile-Asmussen]

Getting a different but probably related error in this file:

https://github.com/Kile-Asmussen/proxy_mtg/blob/929b78887dc91031787ab4690caa7dd29c455349/css/card-geometry.css

Invalid block at line 410:1

[Kile-Asmussen]

These files are large and pretty complex, using calc, content with unicode characters and the like.