Does this happen when opening a document in Photoshop? It sounds like the document itself is corrupted. Hopefully, you have some redundancy tools in place like System Restore in Windows or Time Machine on Mac. Otherwise, you've just learned a hard lesson. 😞
In the future, for mission-critical documents, stagger your saves; "My Document 1," "My Document 2," etc. That way, if a document becomes corrupted, you can refer to an earlier save.