[13:47:10] [Client thread/FATAL] [tconstruct-API]: Could not register material "alubrass" from Materialis (materialis): It was already registered by Tinkers' Antique (tconstruct)
[13:47:10] [Client thread/FATAL] [tconstruct-API]: Could not register material "alumite" from Materialis (materialis): It was already registered by Tinkers' Antique (tconstruct)

This happens with material conflicts in 1.12.2, you can disable these materials in the materialis config or the tinkers antique config if it has one. Disabling one of the two will fix this.

Understood. Let me see if that fixes it.

It does but I didn't find the materials in both configs so I'm just going to leave it like that.