Whenever you get an error in your spreadsheet, you will see a green triangle on the left of the cell, where the error is; Follow the steps below to turn off the green triangle.
Click the File tab.
Click Options on the backstage view.
An Excel Options dialog box will open.
Click the Formulas tab on the left pane.
Under the Error Checking section, uncheck the check box for ‘ Enable background error checking.
Click OK.
The green triangle in the error cell is removed.