Why does this keep popping up?

Lately, when I've been working in an assembly, and doing some measuring, when I click on a surface the program will hang up for moment, and I get a box that says:

"Want to save you rchanges to 'SW Drawing TEmplate.xlsx'?"

Does anyone have any idea why this is happening in an assembly, and how to stop it?  Thanks.

SolidworksAssemblies