1c. If a cloud drive fails the checksum / HMAC verification, the error is returned to the OS in the kernel (and eventually the app caller). It's treated exactly the same as a physical drive failing a checksum error. StableBit DrivePool won't automatically pull the data from a duplicate, but you have a few options here.
First, you will see error notifications in the StableBit CloudDrive UI, and at this point you can either:
Ignore the the verification failure and pull in the corrupted data to continue using your drive. In StableBit CloudDrive, see Options -> Troubleshooting -> Chunks -> Ignore chunk verification. This may be a good idea if you don't care about that particular file. You can simply delete it and continue normally.
Remove the affected drive from the pool and StableBit DrivePool will automatically reduplicated the data onto another known good drive.
And thank you for your support, we really appreciate it.
As far as Issue #27859, I've got a potential fix that looks good. It's currently being qualified for the Microsoft Server 2016 certification, Normally this takes about 12 hours, so a download should be ready by Monday (could even be as soon as tomorrow if all goes well).