I did check the numbering plan and found nothing of consequence. Thanks for the procedure in case I need it in the future.

I still can not get past this invalid response to dialing the hunt group access number when all of the stations are on DND. I verified that 10.71.2 STL CampOn Busy was enabled for the voicemail ports. I also tested it by calling our back door access number and entering my own extension. The call rang to my "in use" phone without any trouble

Note: I am seeing the invalid message on my two line display (non SLT) digital telephone set. I don't think 10.71.2 would affect this operation anyway. I just happen to get the same behavior when using a voicemail port.

I have a work around: Since the "invalid" response to dialing the hunt group access number is a busy signal on an SLT, I will allow the call to recall back to voicemail as a consultation and send the call to the attendant from there. It is a bit kludgy, but I think it will work.

However, If the invalid is a result a poor programming choice, I would love to know it.