Firstly have you checked the Help & Advice
for the Result Set Exceptions Report
from within Plugin?
See Knowledge Base > Show Project Statistics ~ Result Set Exceptions Report
There it explains how to locate such items on the All
tab, which is standard Result Set
feature many don't know about.
Also for that exception it says it's due to rare Birth/Christening/Adoption Event link to Parents Family
I spend hours writing that advice but it seems it is often not consulted.
In this case it is a perfectly valid GEDCOM
structure, but rarely used and somewhat hidden in FH
So when it exists it is usually due to an import from another product and the user does not know it is there (like you).
That is why I flag it as an exception, not an error, as it is simply unusual.
To get rid of it, use Delete in the usual way.
BTW: I use Parents Family
in the same way as FH
as opposed to Spouse Family
. It is a reference to that form of GEDCOM family link, not to the parent's family as such.