Be sure to unplug all SA devices from USB, except the Ventris. Make sure you have no software running that could have identified Ventris as a USB device. Plug Ventris in directly rather than via a USB hub.
While it is awesome the our One Series pedals can show up as midi devices and work with DAWs, we just discovered that this is a key reason folks were having a host of troubles when updating (including getting bricked pedals). What can happen is right in the middle of the critical part of the update, the midi software tries to talk to the pedal and corrupts the data. If you think about it, it makes sense and gives some insight into how hard this problem was to discover. We got punished for adding a cool feature! This warning is designed to prevent this from happening. Hope this helps.