I am having similar problem. If I save the file to OneDrive on computer A, then try to open it on computer B, I get the same error as above. THIS IS NOT A WORD PROBLEM AND THE FILE IS NOT CORRUPT. If I email the file from the OneDrive folder on computer
A to computer B, and then open the file attached to the email on computer B, it works just fine. ONEDRIVE IS DOING SOMETHING TO THE FILE to cause it to be "corrupted." I have had similar problems with Excel files saved to OneDrive.
OneDrive is great for saving everything BUT OFFICE FILES. The more integrated that OneDrive becomes with Windows and Office, the worse it gets. I have 115GB for free with OneDrive, but its becoming unusable because of these problems. I suggest using DropBox
for your Office files (this also works better for Office files that you want to open on the iPad).
Will Microsoft ever fix the problems with OneDrive and Office files? I doubt it because you can't get ANYBODY at Microsoft to even admit that OneDrive is altering the file much less corrupting it. But it clearly is!