I recently purchased a dolica tripod. I am looking at the user manual. Under the ball-head, there is a ring. I am not sure what to call it. The ring has come off and I am unable to attach the ball head with the ring in place.
The ring is the top most part of the center column on which the ball head sits.
In this case, this ring has come off and I am unable to screw it back in. I suspect this is a manufacturing fault. This tripod is less than 2 weeks old.