So if Becker01 and orbyxP download and copy in my file containing the paired xdp and bdp files (not using JSGME, but making a backup of the aircraft folder), and then run BDPStamp from the WOFF Toolbox this should square everything up, assuming that we are all on the same patch 1.35 and no one has modified any of the 3D models. When a campaign mission is then started there will be no mass regeneration of bdp files and everything should be OK , assuming that is the problem. Although, of course, as you say, the problem may be caused by JSGME time stamping files so that they can be rolled back....