Thanks for the message.
Unfortunately, I'll need more information to give you a proper help. First of all, could you send me your log (help>export log..), so I can dig deeper into your project ? Are your layers still intact ? Could you share a screenshot of the Substance Project ?
In the meantime, you could try to load an autosave to see if the problem persists. You could also make sure your graphic drivers are updated.
Keep me posted.