What to do?
Also check to be sure you have the cron running, and folder permissions, this can effect new installs.
There is a conflict on your site
this breaks the newsfeed plugin.
Please remove all add-ons you have recently added
If the problem persists, try uninstalling and installing the newsfeed plugin.
Additional note: Check if admin and other pages are working on your site.
If pages like groups-forum-admin are opening, the problem is only in the newsfeed.
Try passive plugins to get to the source of an error
If there is no access to the admin panel, you can disable it by doing plugins (0) via mysql. Please make sure it is the right column.
Passive in order You should be having problems with the passive plugin that last affected the improvement.
Some plugins can corrupt the mysql database of other plugins.
In this case, restart mysql from the WHM entry is a warning if there is a corrupt table.
If Cpanel is used, login to PhpMyAdmin and select all tables and apply repair option.