First, this is not a good bug report. What is the error you get (if any) when you try to use an owl? Second, did you have this Owl in your inventory? I believe the Cash Shop is disabled in the beta right now
(Sorry for the bad bug report) I can't remember the error code but I bought the owl from the guy in FM and when I went to search for a red craven the game quickly crashed and an error code starting with something like 2147 popped up. I understand a few people in my guild have also had this problem as well with other items.