[3.0]: Popup overlays no longer work

[Sesquipedalian]

Basic Information

Clicking on a link that is supposed to create a popup overlay, such as a help icon, no longer opens the content in the expected overlay. Instead, the entire web page goes to the target URL, just like a normal link would.

Steps to reproduce

1. Navigate to any admin page and click on a help icon.

Expected result

The help text overlay appears and shows the help text, like this:

Actual result

Browser goes to a separate page containing the help text, like this:

Version/Git revision

3.0 Alpha 4

Database Engine

All

Database Version

N/A

PHP Version

N/A

Logs

JavaScript console reports the following error:

[Error] ReferenceError: Can't find variable: $
	Global Code (script.js:1377)

Additional Information

This bug was introduced in #8884

[Sesquipedalian]

@live627

[live627]

18:02:19.286 Uncaught TypeError: can't access property "querySelector", oContainer.cover is undefined
    reqOverlayDiv http://localhost/smf-dev/Themes/default/scripts/script.js?smf30alpha4_1761181104:264
    onclick http://localhost/smf-dev/index.php?action=admin;area=featuresettings;f4df005ada=b06d0dbada284124efcc83140c173eff:1
script.js:264:22
18:02:19.796 Uncaught ReferenceError: $ is not defined
    <anonymous> http://localhost/smf-dev/Themes/default/scripts/script.js?smf30alpha4_1761181104:1377
script.js:1377:1