Okay, I might have found a solution to this... If you go to the explorer in the editor, you get a list of all your logics. If you delete the logics that have disappeared and undo the deletion, they pop back in!
I've been having the same issue whenever I test my game in the editor. When I go back into the editor I see this:
I'll link the output_log.txt and the output_log_clean.txt as well!
output_log.txt
output_log_clean.txt