[FYI]
A Player of our world would automatically get booted when I placed any block down of the create mod. Come to find out it was related to him using the light overlay mod that has gridlines.

This issue has been marked as stale because it has been inactive for 3 weeks. It will be closed if it remains inactive for another 3 weeks.

This issue has been closed since it has been inactive for 3 weeks since it was marked as stale.

Is there a server/client crash log?