Well, this is one for the Weird Robot News Weekly rag.
I was puttering around doing SafeOp setup on a KRC4 running KSS 8.3.39, and when I went to switch to the Diagnostic Spaces View, the HMI froze with this popup. Well, no big deal, right, just reboot from the power switch.
Except the robot rebooted to the same popup. Couldn't do anything with the HMI at all.
Reboot again. This time, the SmartPad never gets past the "initializing robot display" message. Try a few more reboots, no luck.
Disconnect the SmartPad entirely. Connect via Remote Virtual Pendant. Nothing but a white screen with popup.
Try WorkVisual. It can connect, pull the Project, and remotely take an Archive, everything works.
At a suggestion from KUKA Tech Support, tried plugging in a DVI monitor directly and rebooting. HMI comes up perfectly. Hot-plug the SmartPad, it kicks out the monitor and... SmartHMI displays perfectly on the Pad, as if nothing had ever gone wrong. 
These robots... sometimes, you just wanna strangle 'em.
Oh, well. Hopefully this is helpful for someone else who runs into this problem, someday.
