Jeff, that IS indeed a sign of the dreaded HDMI board failure.
If however, you need Networking to reload your Pro calibration, here's something that tends to work. BTW, I assume you're still getting audio from the unit from HDMI sources since you didn't mention that disappearing?
In any case, in the early stages of the HDMI board failure, it can be possible to restore full functionality by toggling various settings and powering the avr on and off (might be helpful especially if you want to restore a calibration for guests etc.).
Go in the menu to HDMI and toggle the ARC settings on and off and power cycle the avr after toggling. Check the menu a few seconds after powering the avr On. This weird ritual can restore audio if audio is lost due to early stages of HDMI board failure, and will also restore full Menu options. It's only a workaround though, as in the later stages, it will take longer periods of toggling to restore functionality, till the terminal stage, when no amount of toggling will do anything.
Thanks, Max. So far, loss of networking is my only symptom. I'll run MultEQ XT 32 this afternoon. Before doing that, I'll try your workaround as I'd prefer to reload Pro . In any case, I only need to get through the next week with guests before taking it to the nearest authorized center.