I also just upgraded to 1.2.5 BuddyPress this morning and have this same problem.
Using normal wordpress dashboard I cannot delete user… results in error message:
Fatal error: Using $this when not in object context in /###/wp-content/plugins/buddypress/bp-groups/bp-groups-classes.php on line 1053
*Note: I am not using “SuperAdmin”.
*Note: I am using “Fluency Admin” however. Shouldn’t be the issue.
When trying to delete user from front-end members page it simply does not delete the user at all. No error message or anything, it just doesn’t delete the user.