Enable the "Insert Rows" with mouse Right Click in Microsoft Excel

To fix this Issue, just follow below steps:

1. Close all you Microsoft Excel files
2. Goto "%appdata%\Microsoft\Excel" in Windows explorer and rename Excel15.xlb to Excel15.old
3. Start Excel and you will see the 'Insert Row' function is now active.

Now you are able to find "Insert Rows" Enable. 

What is .xlb file ?

XLB is a settings file format created by Microsoft Excel. XLB files contain custom settings for the toolbars (or command bars). These settings can be edited or customized by selecting “toolbar” from the view options. XLB files can contain information such as which toolbars are visible, their position, and their function. XLB files allow for the transfer of customization information between computers and users.