404 error page not found when trying to edit existing entry

Same issue. In my case, I figured out that when the update contained anything that might be interpreted as executable (e.g., adding a link that starts with “https://www.”), the form failed. If I made the change with out that (e.g., link starts with just “www.”), no 404, changes saved.

By the way, if that same edit is made through the front end form (e.g., user enters a link starting with “https://www.”), there’s no error.

For what it’s worth.

Kristin