A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
I tried all the listed possible solutions and unfortunately I had no success. However, I did find another solution that worked for me.
Go to the Trust Center in Options and click "Trust Center Settings."
On the left pane, click on "File Block Settings" and check the boxes under "Open" for all previous versions of Excel.
At the bottom, make sure the circle for "Open selected file types in Protected View and allow editing" is ticked otherwise you won't be able to make any changes to the file.
Try opening a file that would normally open blank and see if it goes into protected view.