A contextual filter does not limit the results, it only adds additional input to the view based on certain situations.
It may be a problem with the relationship.
Please check that Require this relationship is not ticked. If it is then by its description "Enable to hide items that do not contain this relationship".
If you just add the relationship but not require it, a field taken from the relationship will only display as a blank space in your rendered view.
Hope this helps. I had the same problem before.
Update 2014/06/20
I'm assuming the view displays users.
Contextual Filters
- add User:Uid -- When the filter value is NOT in the url, provide a default value -- User ID from logged in user.
This filter will set it to display based on the current user.
Relationships
- User relationships: Requester user -> use the contextual filter on this
You'll have to play around with this as I'm not sure.
Sort Criteria
Fields
- UID: (this will display all the user IDs)
(check first after adding this that ALL users are displayed.)
- Relationship Type
- UID: (use the relationship)
Try adding the first field first then adding all the contextual filter, relationship stuff. It has to display ALL the users.