I have a client with teachers that use Mac's and are in a Papercut environment. Recently, some of the Mac's, but not all, will spool for a while when printing PDF's and then give an error message [filter failed] and then the print job locks up the print queue on the Sharp. I don't have the operating systems versions that the Mac's in question are running, they are gathering that information for me and I suggested they consult Apple about updates. I and they understand this isn't an issue with our equipment or Papercut, I am just reaching out to see if anyone knows the answer to this issue, thanks.