My scanned documents show up blank in Scan Pro App. What can I do?
This is most likely a synchronization problem. If you've been using the iCloud Drive Sync before, please make sure that it is still turned on and wait for a few minutes without leaving the app.
Sometimes it can occur that a document will encounter some problems during the saving process.
This lets documents appear blank and unfortunately there is no way to retrieve them since they couldn’t be created in the first place.
Thumbnails are created prior to the creation of the whole document, which is why you are able to see them.