SuperMicro iKVM Video Only
Frustrated that the IPMI iKVM session on your brand new SuperMicro server says “Video Only” at the top and your virtual keyboard won’t work? I was. I’m sure the culprit could be any of a number of issues, but for me it was a BIOS setting.
I was messing around in the BIOS (a.k.a. “asking for trouble”) and I changed the number of USB ports from 12 to 4. I guess the virtual keyboard is “plugged” into number 12. Or something. Anyway, I guessed (and the manual confirmed) that they all have to be enabled for iKVM to work properly. That solved my problem.