Close the program. Restart and, before attempting to load the project, go to OPTIONS | DISK tab and Clear Unused Cache Files.
If you have used Save AS routinely there may be an earlier VPJ control file on the PC. Try double-clicking it.
If still no go, zip the folder that contains all the source files (+ the VPJ file) and share it. Someone will take a look.
The process is easy, quick and can be done privately. Just follow these steps. Don't skip any. And if using Google Drive for the upload, don't forget to change "restricted" to "anyone with link can view."
Back up --- With your project on the timeline, click on MENU at the top-left. Click FILE|BACK UP PROJECT FILES TO FOLDER. Choose a folder and SELECT FOLDER.
Upload --- Use a free server - Google Drive, MS OneDrive, etc.* - to upload the saved, numbered FOLDER. No need to upload the individual VPJ or export file.
Get link --- Right-click the file and click SHARE. If using Google, right-click the file, click SHARE | SHARE. Change "restricted" to "anyone ... can view"
Share --- Click COPY LINK or OK | DONE. Paste that link here, or click the folder at the top-right of this forum to message it privately. It won't be shared.
* Before uploading, right-click the folder, click PROPERTIES. Look at the File Size to confirm that it's not too big for the free space on the server.