I'm stuck on Creating a Controller Extension.  My increment button is not displaying and I've started the exercise over from scratch now 3 times.
What am I missing that the button does not appear?

I'm getting this error message:  Error: This report cannot be used as the source for this component. If it is a summary or matrix report, add one or more groupings in the report. If it is a tabular report with a row limit, specify the Dashboard Settings in the report.

I don't know how to fix the data source 

I'm stuck on Creating a Controller Extension.  My increment button is not displaying and I've started the exercise over from scratch now 3 times.
What am I missing that the button does not appear?

I'm stuck on Creating a Controller Extension.  My increment button is not displaying and I've started the exercise over from scratch now 3 times.
What am I missing that the button does not appear?