Step by step approach to troubleshooting -
1) Clean out your machine. Delete all local files, backup files. In the Windows Search box, type in %temp% and when the Temp file opens, delete everything. Skip the items that Windows does not want to delete. Clear Recycle Bin
2) Try to reopen the project again
3) If this does not work, try to replicate the behavior on another machine. Try with your log-in, and then with someone else's ID.
4) If your log-in does open the file, then your user ID could be corrupt. In which case you may need to do this - https://knowledge.autodesk.com/support/revit-products/troubleshooting/caas/sfdcarticles/sfdcarticles...
If none of these work, then submit your file and the backups to Autodesk they can try to recover the file.
Create a case on your https://manage.autodesk.com login page.
How to make a case with Autodesk instructions https://knowledge.autodesk.com/customer-service/account-management/subscription-management/support-o...
Rina Sahay
Autodesk Expert Elite
Revit Architecture Certified Professional
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