Our top referral is Self/Friend, and we had that set up as a referral. It's all of the sudden missing, which I didn't think it would let you delete once it's attached to patients' charts. It's missing altogether from the system. I need to have it resurrected, and if need be a data merge to set everyone with no primary referral set, have a batch job run to reset it back to this referral.
Have you tried searching for a specific patient who is attached to the referral "Friend/Self"? I only ask this because this happened to us last year with one of our top referring doctors. All of a sudden he was no longer in the system. I don't know how it happened but his name somehow got changed to another provider's name. We were able to change it back and have not had a problem since. The only way we could figure it out though was to locate a patient who had recently been referred by that doctor to see what was coming up for them.