1. In 1.12.2 the ender io sagmill and alloy smelter are called block_sag_mill and block_alloy_smelter(it is manually fixable in the configs though)

2)Even if you manually fix the ender io sagmill and alloy smelter the gui won’t show up

3)Re-add all the upgrades(at least the ones that disappeared)

4)The same issues/Problems also happens on the Engineer's Workshop Reborn so don’t force me to use that mod