whenever I try to download the pack I get "Failed to get mod loader (fabric-0.13.1-1.18.1), check manifest!"
importing it as custom profile doesn't work either

Please use another Modlauncher (e.g. MultiMC) until Curseforge has fabric 0.13.1 available.

Mistake on my side, will not happen again. With the next version all will be back working.