Hi!
That’s a bug in the constraints on Wikidata – “date of
birth” has a
constraint stating that its value must be at least 30 years away from
the “date of birth” value. We’ll work on resolving this (I contacted
Ivan Krestinin, who added this “experimental constraint”, to ask if he
still needs it – and if it can’t be removed from the P569 talk page for
some reason, we’ll probably filter it out in the user script).
The checks seem to be against P184/P185, of which neither is on
Q5066005. So I suspect there's some bug still somewhere.
--
Stas Malyshev
smalyshev(a)wikimedia.org