Playing on Engineer's Life, got sick of not being able to combine slabs.

Seems to be triggered after walking over vertical planks.

See attached log.
crash-2020-06-26_00.09.12-client.txt
crash-2020-06-26_00.05.54-client.txt

Seems a very specific doorway only, any other passage way works, I don't get it.

This is a duplicate of #70