Try using a different browser and make sure that your internet connection is stable. If you are using a Desktop version please make sure it is updated to a current version. Please verify that none of the forms you are using are locked: TurboTax FAQ: Why does TurboTax say my forms are locked or haven't been finalized? 

If you are not using any locked forms, we suggest you to contact our Product support team. They have access to tools we don't have here in Community, like screenshare to investigate this issue for you.  

Thank you for choosing TurboTax.