I recommend that you use a separate directory (under C:\ somewhere) with your development directory, utilities that are portable like Anim8or, and you texture directories/save WIP folders. Stuff under Users/ kinda gets goofy with permissions and stuff these days. Sometimes just windows indexing or some sort of AV or "Cloud Storage" data stealing stuff that pretends to be a backup system can suddenly create a situation where a utility can no longer access a resource. Look at its currently indexed location in your texture list, then remove/replace it, and see what the difference was. That stinks when you have like 30 textures...
