Excel notification " File in Use" is not working

Does anyone know why the pop up window that displays:

File in Use
Tester123.xlsx is locked for editing
by 'another user'.
Open 'Read-Only' or, click 'Notify' to open read-only and receive notification when the document is no longer in use.


Example:


Is not working on a Windows 7 machine running Excel 2010

https://community.spiceworks.com/top...n-mapped-drive