I've recently upgraded my windows 7 to windows 10 enterprise. I have onedrive account with files synced to cloud, before upgrading i've backed up onedrive files locally in my computer. Some of those files can't be opened after upgrade, formats include .docx and .xlsx and .png. Most of these files were in direct onedrive main/root folder rather than in subfolders. As i can see those images in subfolders can be opened but not doc and excel files.
How can i view those files again, why have they become corrupt, what could I do in future to prevent these problems