Clicking "Install JIRA Agile for project management" on "Guide for JIRA Administrators" loads indefinitely

Expected Behavior

Installs Agile

Actual Behavior

The screen darkens and loads indefinitely, on the browser's console we can see a JavaScript error message (see screenshot).

Steps to Reproduce

1. Install JIRA;
2. Click the link "Install JIRA Agile for project management" on the "Guide for JIRA Administrators" gadget at JIRA's System Dashboard while logged in as a System Administrator;

Workaround

The current workaround is to install Agile through the other available ways, either through UPM (1) or by clicking "Agile" on the top bar (2).

Workaround #1

1. Go to Administration > Add-ons > Find new add-ons;
2. Search for JIRA Agile;
3. Install;

Workaround #2

1. Click the Agile item on JIRA's top bar;
2. Click Install JIRA Agile on the pop-up;