500 error creating a subgroup

Summary

When creating a subgroup via the "new subgroup" button on the group page, users are given a 500 error.

Steps to reproduce

This occurs in our QA gitlab, running version 13.9.4. On the group page, click the "new subgroup" button. However, via API, creation of subgroups works fine. Group and subgroup creation runs without issue in our production gitlab, running 13.8.4.

Example Project

What is the current bug behavior?

500 error

What is the expected correct behavior?

"New group" page

Relevant logs and/or screenshots

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

(For installations with omnibus-gitlab package run and paste the output of:
`sudo gitlab-rake gitlab:env:info`)

(For installations from source run and paste the output of:
`sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`)

Results of GitLab application Check

Expand for output related to the GitLab application check

(For installations with omnibus-gitlab package run and paste the output of:
sudo gitlab-rake gitlab:check SANITIZE=true)
(For installations from source run and paste the output of:
sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true)
(we will only investigate if the tests are passing)

Possible fixes