Unable to create new Merge Request to gitlab-org/gitlab on gitlab.com

Summary

I get a 500 internal server error when creating a new Merge Request from a branch on my fork of Gitlab to gitlab-org/gitlab

Steps to reproduce

• Fork Gitlab
• Create a new branch and make some changes to that branch in the fork
• Attempt to create a merge request from this branch to the main gitlab-org/gitlab project

Example Project

What is the current bug behavior?

When I attempt to create an MR from my fork to the gitlab project, I get a 500 internal server error

What is the expected correct behavior?

A new merge request should be created from my Gitlab fork to the main Gitlab project at gitlab-org/gitlab

Output of checks

This bug happens on Gitlab.com