Error on Project Milestone pages

On this page on my local GDK:

http://localhost:3001/groups/h5bp/-/milestones/sprint-natus-illum-rem-ea-omnis-repudiandae-repellat?title=Sprint+-+Natus+illum+rem+ea+omnis+repudiandae+repellat

The chart does not load, and I get this error:

[Vue warn]: Cannot find element: #delete-milestone-modal

delete_milestone_modal_init.js:54
<anonymous> index.js:8

We should maybe add null check to app/assets/javascripts/pages/milestones/shared/delete_milestone_modal_init.js