I tried to block a group which sent me an unwanted invite, using the block button when viewing the group page, NOT using the block button on the notification. Unfortunately, clicking the button to confirm the block does nothing. Upon looking in the inspector I saw the server was returning the following:
{"error":{"message":"You must leave a group before blocking it․","status_code":403}}
However I am not joined to the group at all.
So:
#1 Please fix it so I can block groups that send spam invites
#2 Please display this error message to the user instead of having the page appear to ignore the user's input