The setting that controls your ability to see this indicator is off by default. To turn this setting on, follow these steps:
Open a calculation and select the sheet you want to work with..
On the toolbar ribbon, select the Tools icon and select
Settings
.
Select the
Template override indicator
box.
A red exclamation mark in a cell indicates the cell contains a template setting that was overridden.
To view all template overrides:
Open a calculation.
On the toolbar ribbon, select the Tools icon and then
View all template overrides
.