Yes, this is fascinating. When we craft the UseSkillRequest for summoning clip art, we specifically set "this.countFieldId" to null, since you cannot legitimately specify a count. However, setTarget sets this.countFiledId to "quantity". The question is: why is setTarget being called for a clip art request?
I think I fixed that yesterday when figuring out how a UseSkillRequest which was correctly set up to cast a buff on a particular player was actually munged before being submitted to cast it on yourself: the process of registering the request ended up modifying the request!
I believe that is what happened here, too, and I believe that my fix for yesterday's problem will also fix this problem.
I just cleaned up the cast skill loop in UseSkillRequest to move some stuff out of the loop (a speed optimization, but which shouldn't change observed behavior) in revision 14229, but, as I said, I think I fixed the issue yesterday.
I'm going to mark this Waiting For Info. If you guys can't reproduce the problem any more, by and by we'll mark it Fixed.
