I have two machines on which I have installed production release 1903, Windows Sandbox runs on one, but on the other I get Error 0x80070015: The device is not ready. I have searched through the event log and can't find any events that appear to be related. I'm not even sure where to start.
I've read some articles from the pre-release that indicated that they found log entries somewhere, but found no details on where else to look. I looked through all the Hyper-V log groups I could find with no luck.