I won't "answer", since I don't have the power to fix anything, but I have a guess about what probably happened. The recent European regulations that go into effect soon have made Wikitree lock the profiles of persons who may potentially still be alive. Since you added a birth date that is less than 150 years ago, the profile instantly became locked as a potentially living person.
I think we're all going to have to proceed very carefully from here on out when we edit profiles. It's too late, but if you had happened to know this person was deceased and put that information in the profile first, it probably wouldn't have locked up.