Has any body else had such an issue? I have spent hours trying to get them back. It's as if they have just died one by one over a period of a several months.
Just cannot get any of them to work again.
It seems you lost all these cameras with "no signal" in Dec. of 2018 when your modem was defective but got them restored to operation by using the Sricam app as suggested by SouthernYankee.
Is it possible that your Blue Iris server and the cameras are not configured with unique, static IP's, all in the same subnet, and the IP's have changed perhaps when power has gone off/on or "glitched" these past months, causing the cameras to go offline?
Four days before the "No Signal" issue my internet went down and it was confirmed by my ISP that my Modem/Router (Netgear C6300BD) had failed.
I installed a another modem which had also been supplied by my ISP some time back which does not support port forwarding and the Internet returned ok. Now with Blue Iris running I noticed all my cameras where displaying "No signal" . I looked at all the settings in the modem and Blue Iris to try and get my cameras to work to no avail. My first thoughts were that this unused modem had a problem because before this "No Signal" issue...