I discovered the same error with a person in one of my online trees just last night. Suddenly I found that I had this one person linked to the right spouse but also to a child as his spouse. I did the usual and checked to see if somehow I had entered the same person twice which was not the case. I then went to the edit and relationship tabs and discovered that this child was both a spouse and a child. When I severed the wrong link, things went back to normal. That is the best way to proceed after one has checked first to see whether a profile has been entered twice.