The energy content levels from this type of products are lethal.  An accidental release of the surge onto a human body has to be avoided.  All the output ports of the surge generator circuitry and AD/DC CDN are completely protected by the custom design high voltage interlocked connectors. 

The messages are a result of functioning of the safety interlock circuit.  Only when all the ports to be used are plugged with the output cables and all irrelevant ports are covered by the dedicated safety cap, the high voltage circuitry can be activated.