Via Template Manager I made a copy of the Xenon theme Particles. Then I clicked on the Assignments tab in the Xenon template and an empty pop-up appeared. Apparently the system wants to tell me something, but there's no message.
Closing the pop-up does not activate the Assignment tab view. Clicking "under" the pop-up makes the Assingment view available though. Clicking on a different tab first and again on the Assignment tab makes the Assignment view also available.
I have tried this both in Chrome (48) and FireFox (44).
This is the div of the empty pop-up that appears: <div class="g5-content" aria-live="assertive" tabindex="0" style="width: 90%;">
Please would you post your URL, superuser id and pswd in the secure tab of your post and i'll have a look for you.
Give me the exact steps to reproduce the issue.
Make sure that you have everything up to date (joomla, gantry, rt extensions and template) - backup befor eyou update anything.
Regards, Mark.
Please search forums before posting. Please make sure your post includes the version of the CMS you are using and a link to the problem. Annotations on screenshots can also be helpful to explain problems/goals. Please use the "secure" tab for confidential information.