For many years I've kept a basic convention for my keyswitches in VE Pro 2, which are all in the octave below the end of an 88 note keyboard (I do this to trigger them from a little Nanokey that sits on the master controller). By the Default setup in VSL nonclemeture, this starts at C0 going up to B0. While I was setting up a new instrument today and setting all the keyswitches to my standard, something bizarre has happened - no keyswitch now responds to C0. Anything C#0 upwards is fine. I can see the midi getting though normally onto the VI Pro GUI keyboard - it flashes away as I hit C0. So midi going in is ok, all other keywitches are ok, but C0 stubbornly refuses to switch.
Moreover, it behaves like this now on every single existing patch, part of my templates for years. I've not touched any of them, so its clearly a global setting somewhere that has gotten changed or something is corrupted. I can see 2 keyranges top right of the GUI in VE Pro, and they are both set normally (not that I should be using them). I've restarted VE Pro and indeed the entire rig, but no matter what I do C0 fails to switch. Reinstall VI Pro perhaps? Grateful for any and all help.
VI Pro is on 2.4.16779 - Win 10 Pro.
EDIT - updated to 2.4.17181, no change to behaviour sadly.
EDIT 2 - tried player in Cubase and standalone, bypassing VE Pro completely No change to behaviour.