[DCP-o-matic] DCP won't work

Hi there! I am using the most current version of DCP-O-Matic on a Mac system. Following the instructions I authored a feature-length DCP to a mac formatted drive. Everything seems to check out. The projectionist at the theater reported that the drive would not work at all (due to their system being a PC). I then created an Ex-FAT drive with the same DCP package files, but the Projectionist reported his system could not see any packages present to load. What should I do? We have an important screening in a few days. I do not have access to a PC - is there any way that I can create a workable DCP using a mac? Regards, Evan Sent from my iPhone