Open a document after a file corruption error
1. Click File > Open, and then go to the location or folder where the document (Word), workbook (Excel), or presentation (PowerPoint) is stored. Don't try to open the file from the Recent section as this won't go into the Open dialog box.
2. Click the file you want, and then click the arrow next to Open, and click Open and Repair.
Preventing file corruption in the future
Problems with file corruption typically happen when the file is stored on a USB device that is disconnected while the device is open in Windows. You can prevent damaging files by using the Safely Remove Hardware icon in the Windows taskbar. If you don't see the icon, click the up-arrow in the notification area to show hidden icons.
In the event of a crash or loss of power, you can recover a previous version of your file if you turned on the Autorecover feature in Office.
For more information about recover unsaved document file, please check this tutorial:
https://r-datarecovery.com/4-efficient-ways-to-recover-unsaved-word-document-without-obstacles.html