Chris,
I seriously doubt it is any kind of bug in Project but it could be a "bug" in your file (i.e. corruption). Let's check a few things.
- Is your version of Project fully updated? If not or you're not sure, run Windows Update. The latest update is Sept 2016 and that will give a version of 14.0.7173.5000
- Are all your tasks auto-scheduled?
- Do you have calculation set for automatic?
- Have you leveled your plan?
- Does your file use a resource pool file?
- Does this happen with any file you create or just this one file?
John