How to solve Protel "Warning - net contains unplated pads" ?

Dear Sir:
When I DRC in Protel DXP I get much this message
"[Un-Routed Net Constraint Violation] PCB1_998.PcbDoc Advanced PCB Net
DSP_AAOE
Warning - net contains unplated pads "

Someone can help me? thanks a lot!

 

Thanks Graham Holloway and Peter Bennett.
The problem had solved just as you said.

I have a new problem in DRC message
"Warning - Pad/Via touching plane splitting primitives"
Although I can disenable this option in DRC'option,But I want to know
if this is a really problem.
Can someone give me some advisement. Thanks