Hi,
Where did you save the file?
What kind of file format is the document?
NOTE: Please back up the document first.
I suggest right click the problem Word file- select Properties- General tab- check the Unblock option- click OK.

If this method is not helpful, you can try to open the document in safe mode:
Running the following command: Press Win + R, type "winword /safe" in the blank box, press Enter- then open the document in safe mode. If it works fine in safe mode, please check the add-ins in your Word and disable them.
You can also try to the Open and Repair option, open a blank Word document- go to File- Open- Browse the problem document- click the small triangle arrow icon in the Open button- Open and Repair:

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