temp fix:
line 115 of railcraft.cfg
tweaks.minecarts.bore.mineableBlocks={ 140:2, 140-1:2, 140-2:2, 140-3:3, 140-6:3, 140-7:2, 198:1, 247:4, 248:3, 249:2 }
remove all of the id's
tweaks.minecarts.bore.mineableBlocks={}
this lets it load with no issue apart from the tunnel bore being unable to mine some blocks. Dunno what the real problem is though, just figured out how to get it to run. This is a probably a minor issue anyway.