Have the same issue. However, I do not have the “group extras” plugin, and even if I did, I cannot access it because my site cannot be accessed after I activated your plugin; any page comes up as this error message. Basically, it crashed my site.
Fatal error: Class ‘BP_Group_Extension’ not found in D:\Hosting\11793287\html\wp-content\plugins\bp-gallery\includes\bpa.group.php on line 21
Would really appreciate some help instead of using a backup to fix this.