@anomalaus I am using PMD (external binaries) all the time now since P10. In the P9/P10 beta time frame there were a lot of bugs fixed with regards to PMD corruption. There are still some things to be aware of. All filenames in Poser have to be unique - regardless of filename. This means it will reuse the same file if it encounters it again (regardless whether it is the same file or not). When you save a scene with external binaries, it will create a PMD with the same name as the scene. If you have named the scene the same as a figure you have loaded (with an attached PMD file), Poser will now prevent you from saving the figure or scene with that same name to avoid a naming conflict (scene PMD and figure PMD having the same name) and it throws up a warning message. Solution is to save the scene of figure with a different name. Things can get more complicated when you overwrite a figure in the library. The figure may have been used in another scene and that scene may have had a reference to the figure PMD. If you use the same figure it will be fine, but if there is a change in the loaded morphs, there might be an PMD corruption message if you load that old scene. If you load old (pre P10) scenes you may run into PMD corruption messages caused by pre-P10 bugs which have crept into that scene. One of them was when you used the cloth room. If you had a saved sim and you have done multiple sequential save afterwards (usually 5 or more Save As with a new filename of the same scene), it was possible that a PMD got corrupted because of rounding errors in the simulation. Once it gets over a certain threshold, the scene could get corrupted. This bug (and others) were fixed in P9 and the P10 beta builds. But the corruption message may creep up when you load older scenes which were already infected with the bug. Last year I spend several months to load all my old scenes (several thousands) to find out what they contained and make renders of it and found 2 occurrences of the old bug. Both were created in P8/P9. In both cases i could save those without binaries and re-inject the morphs of the corrupted PMD and recover my scenes. I am using external binaries all the time for the past 5 years and have not had a problem since. There are 2 reasons why I use them. Most important one is that a Save is a LOT faster as without PMD (save of a very large scene is a few seconds instead of minutes) and the scene filesize is a lot smaller as well. If you don't feel comfortable with external binaries, turn it off. It will not prevent the loading of figures or scenes with their attached PMD files. Those are not changed and do not get corrupted. I feel completely comfortable with external binaries,. so I have the option on to benefit from the load and save performance benefits