Edit panel not showing up (Gear -> Edit Panel -> NOTHING??) If I go to a custom panel and click the gear, then click edit panel, the link changes as if a popup appeared, but nothing else shows up. I cleared my cache on my browser, computer, on the website, and even tried it on my coworker's computer but it still doesn't work. I also tried it on Chrome, Firefox, and Safari and still no success.  Any thoughts?
You or one of the modules you installed is loading latest version of jQuery.  In the latest version of jQuery code like 

if (jQuery.browser.msie &amp;&amp; parseInt(jQuery.browser.version, 10) &lt; 8) {}


does not work.

This code is in one of the Drupal core files. You can find it in modules/overlay/overlay-parent.js file on line 932, 975 and 985. 

I do not recommend editing this file, but you can test this change on your localhost to make sure it is the latest version of jQuery which is causing this issue.