I fixed this once before - but since the new portal was introduced it is happening again.
When a player dies in The Erebus, if they are set to re-spawn there, they appear on the bedrock roof.
A player height check needs to be added for re-spawn and bedrock blacklisted as a viable spawn block.
This is annoying as I fixed it once before - I think we should introduce a settable re-spawn point and also default to the portal keystone on dimension entry. This shouldn't be too hard to circumvent the horrible vanilla bed code by using some IExtendedProperties and a bit of code jiggling.

This should be fixed now with the addition of the adventurer's armchair and changes to re-spawn.
Needs a proper road test and some tidying up but from initial testing it seems OK.