Unable to send PM's to administrators

[LLamaman]

In order to receive my t-shirt for getting third place in the Christmas contest, I filled out the PM message box, and then sent a PM to emilk as it said to do so, however, right after clicking submit, the message disappears and where the name "emilk" was, it then said "The requested users to be added do not exist"
I tried sending it to admin, but I got the same error. I tried multiple times, I have not tried sending a PM to a normal user yet, but I doubt that it will work either
If it is simply something I'm forgetting to do, I'm sorry for the inconvenience

[link0007]

Are you sure you entered the subject in the right field? In the subject field, that is, and not in the user field?

[LLamaman]

I think I just realized that, woops,