I've been facing a very frustrating problem for quite a while now, and i've only just worked out where the root of the problem is. It's to do with the setting "On Duplicate Material:" being set to "Replace from Library".
I've made a number of roofing presets, including a roof slate preset, and a ridge tile preset. They are both created in the same master file, so the presets both point to the same file. The objects all use the same multi-sup material in that master file, so that there are not too many materials created... it keeps it neater.
Here is the problem/error: I create a rc object in a new file using the slates, for instance. It has material 1 on. I then create a rc object that is the ridge tiles, which points to material 1. If use the setting "replace from library", when I create the second rc object, it applies the material from the library, and tries to replace the material on the first rc object with this newly "created" material. All well and good, but then I save the file and reset. If I now go to that file and try to open it, Max will crash. The file has become un-usable. The two rc objects are completely broken. I have tried merging everything into a new scene, but as soon as I try the rc objects Max will crash.
However, if I set rc to the other setting; "Use scene material" and repeat the creation steps above, when I make the second rc object it will apply the material already in the scene to the second rc object. I save, reset Max and then re-open the file and it's ok.
I have no idea why this happens, and while the file is still live the materials work fine. It appears that it's just something to do with saving the file when you're trying to apply a new material to an already generated object.
I am using Max 2016 or 2017 (not tested it on others yet) and I'm using RC 2.7.4. I did try upgrading to the latest version but it did not fix it. That was before a complete un-install of RC (registry and file deletion) and re-install to try to work out what the problem was. I'm also using v-ray 3.50.04 set to the default renderer.
Any suggestions? As I have said above, the way to get around the problem is to use the "Use scene material" option, but it might be useful to use the other option at some point?