TypeError: undefined is not an object (evaluating 'n._transitionClasses')

Summary

Change tab of merge requests stays in loading state

Steps to reproduce

Go to the changes tab of a merge request with Safari 13.0.4.

What is the current bug behavior?

The little wheel keeps spinning forever

What is the expected correct behavior?

The actual code changes

Relevant logs and/or screenshots

TypeError: undefined is not an object (evaluating 'n._transitionClasses')
wi — main.8a9cc97b.chunk.js:37:44398
T — main.8a9cc97b.chunk.js:37:59146
(anonymous function) — main.8a9cc97b.chunk.js:37:59368
T — main.8a9cc97b.chunk.js:37:59844
(anonymous function) — main.8a9cc97b.chunk.js:37:60982
(anonymous function) — main.8a9cc97b.chunk.js:37:34455
i — main.8a9cc97b.chunk.js:37:68219
(anonymous function) — main.8a9cc97b.chunk.js:37:26776
(anonymous function) — main.8a9cc97b.chunk.js:37:27659
hn — main.8a9cc97b.chunk.js:37:25767
(anonymous function) — main.8a9cc97b.chunk.js:37:12431
Xe — main.8a9cc97b.chunk.js:37:11826
promiseReactionJob
parseFromString
Qe — main.8a9cc97b.chunk.js:138:35183
(anonymous function) — main.8a9cc97b.chunk.js:138:44772
e — main.8a9cc97b.chunk.js:138:37426
(anonymous function) — main.8a9cc97b.chunk.js:138:45641
each — main.8a9cc97b.chunk.js:14:3008
bind — pages.projects.merge_requests.show.28a44d18.chunk.js:9471
gi — main.8a9cc97b.chunk.js:37:43212
(anonymous function) — main.8a9cc97b.chunk.js:37:42556
di — main.8a9cc97b.chunk.js:37:42858
v — main.8a9cc97b.chunk.js:37:57627
d — main.8a9cc97b.chunk.js:37:56922
p — main.8a9cc97b.chunk.js:37:57384
d — main.8a9cc97b.chunk.js:37:56907
(anonymous function) — main.8a9cc97b.chunk.js:37:61203
(anonymous function) — main.8a9cc97b.chunk.js:37:34472
i — main.8a9cc97b.chunk.js:37:68219
(anonymous function) — main.8a9cc97b.chunk.js:37:26776
gn — main.8a9cc97b.chunk.js:37:26693
(anonymous function) — main.8a9cc97b.chunk.js:37:68242
(anonymous function) — pages.projects.merge_requests.show.28a44d18.chunk.js:26210
H — pages.projects.merge_requests.show.28a44d18.chunk.js:26212
(anonymous function) — pages.projects.merge_requests.show.28a44d18.chunk.js:39777
(anonymous function) — pages.projects.merge_requests.show.28a44d18.chunk.js:39778
(anonymous function) — pages.projects.merge_requests.show.28a44d18.chunk.js:24506:83
r — sentry.39eea7ab.chunk.js:1114:83

Output of checks

This bug happens on GitLab.com