Crash Report or Log: https://gist.github.com/typicalname0/d666cbea20b7db87b6f8e5900c3a2b0e

My friend has issues starting up BuildCraft. I have looked up the error but have found no solutions. He does not use OptiFine

Unfortunately buildcraft isn't compatible with baritone's modifications (cabaletta/baritone#760).

You can either try removing the silicon module, or disabling facades to work around this.