WhatsApp Google Drive restore fails
If your old device is with you


Delete WhatsApp backup from Google Drive. See steps from WhatsApp FAQ
Redo Google drive backup manually (Settings &rarr; chats &rarr; chat backup &rarr; Google drive) and restore


That will create a fresh backup  so corruption is ruled out, though would take longer

Old device not with you but you have copy of database file


Uninstall WhatsApp
Install Whatsapp and  on successfully activating it, immediately disconnect from Internet
Copy the database file into the same folder location from which you copied and restore