False error when trying to view changes while creating a new merge request

Summary

When trying to create a new merge request in a repository or project, you have the option to view what commits will be included and what changes that will entail. This can be found at the bottom of the page.

However, when you press the changes tab (in contrast to the commits tab) you are not only presented with the changes, but also a error stating "Failed to load the page".

From what I can tell this error text is false since everything that is supposed to be on the page is there. The changes are displayed properly and all other inputs made are still there.

Steps to reproduce

1. Create a branch with changes on it
2. Start creating a merge request using the GitLab UI
3. On the merge request creation page (creation form), scroll down to the bottom and press the changes tab (located next to the default commits tab)
4. The bug will appear.

Example Project

Link to a example project. The project contains two branches main and branch-to-be-merged. To trigger the bug, try and create a merge request using these branches.

What is the current bug behavior?

An error stating "Failed to load the page" appears when trying to view the changes of a merge request you are currently creating. The changes are still shown and nothing else seems to be broken.

What is the expected correct behavior?

The changes are shown and no error appears.

Relevant logs and/or screenshots

Output of checks

This bug happens on GitLab.com