"Error updating issue" on https://gitlab.com/gitlab-org/gitlab-ee/issues/

I am getting the red banner reading "Error updating issue" on https://gitlab.com/gitlab-org/gitlab-ee/issues/ when trying to edit the issue I opened about an hour ago.

1. Click edit
2. Add an LF at the end (or anything, to that matter)
3. Click "Save Changes"

Nothing is saved, changes disappear, and the red banner reading "Error updating issue" flashes for a few seconds and disappears.

ADDED But I am able to edit this issue. Just not the issue #3881 (closed)!