Aristois

I've been using polymc to play but I can't figure out how to get it to install since I can't run the installer and prism won't show the jar file.

I want to join my friends smp server but I cant get it to even launch the aristios client without the mods. Here is the game crash error:

The game crashed whilst initializing game
Error: org.spongepowered.asm.mixin.transformer.throwables.MixinTransformerError: An unexpected critical error was encountered
Exit Code: -1

Any help would be greatly appreciated.