It's a common problem in MS Excel. Insert menu becomes grayed out (inactive).
To fixed this problem:
Image 1: Insert menu not working
To fixed this problem:
- First of all close all of your Excel file which is currently opened.
- Then go to this location: C:\Users\your_user_name_here\AppData\Roaming\Microsoft\Excel
- "your_user_name_here" is your user name which user name you are using now.
- There you will see: Excel15.xlb
- Rename it to: Excel15.old
- Now open your Excel file and it is done.