QDF File no longer displays tranactions - how do I restore the file?

To restore a Quicken file, select File > Backup and Restore > Restore from Backup File...

Before attempting to restore a Quicken file backup (or open an earlier copy of the Quicken File), I suggest deleting the Quicken Cloud dataset (aka cloud account) associated with the Quicken file.  Note: You need to open another Quicken file to delete the appropriate cloud account.  You may want to review: https://www.quicken.com/support/how-edit-or-delete-your-cloud-datasets-quicken-windows

This other Quicken file needs to have a distinct file identifier so that we may delete the cloud account associated with the original Quicken file.  For example, you may create a new Quicken file (select File > New Quicken File...) without any accounts, enable sync in preferences so you may view and delete the cloud account associated with the original Quicken file. 

This is necessary because when we open or restore an another version of the Quicken file with the same file identifier, Quicken is not resetting the cloud account appropriately at this time.  I hope they will let us know when they have addressed this issue, but for now before opening another Quicken file that has the same file identifier embedded, delete the cloud account.  

Note: Only File > New Quicken File... generates a distinct file identifier.  All other forms of creating Quicken file, copy the embedded identifier from another file.

DonJ said:

Restore from Backup only works if you have a recent backup....our latest backup was 2 weeks old.

Restore from Backup should work for a backup that is 2 weeks old.  You just have more work to do to catch up.

You could try the Copy and Validate instructions described in: https://www.quicken.com/support/advanced-data-file-troubleshooting-correct-problems-quicken-windows