It appears the Microsoft Excel section is in edit mode. Edit mode is activated when you use in-cell editing or when the insertion ...

It appears the Microsoft Excel section is in edit mode.  Edit mode is activated when you use in-cell editing or when the insertion point is located in the formula bar or the sheet tab. You cannot generate reports while Microsoft Excel is in edit mode.
    
Resolution:
To resolve this problem, press ENTER or ESC to deactivate edit mode, and then try to create report again.