TwistedMexi's Better Build Buy won't work

I've been playing with TwistedMexi's Better Build Buy mod for a while now and never had any issues, but last time I tried to open the filter panel in Build Buy I got this popup.

I redownloaded the mod, put the file directly into the mods folder, but it still doesn't work. I tried joining TwistedMexi's discord, but it says that the invite link is invalid.