User unable to add new users if there's an addition whitespace at the end of username or email address while adding a user to a Team's users group.
After click Add button, the loading icon will keep spinning and both "Add"&"Cancel" button will be disabled.
- Navigate to https://bitbucket.org/account/user/<Team-Username>/groups/
- Click "Add member"
- Enter email address with an addition whitespace at the end
- Click the "Add" button