Ok, it's a little tricky.
In order to copy a cloud drive from one Google Drive account to another, you will need to:
- Detach the cloud drive.
- Copy the CloudPart... folder to the other account.
- Delete the ...ChunkIdStorage subfolder (under the CloudPart) before reattaching the cloud drive.
- Attach the cloud drive from the new account.
If you didn't perform step #3, you will get this error and your drive will unmount:
In order to recover from it:
- Delete the ...ChunkIdStorage subfolder (under the CloudPart) in Google Drive.
- Reset all StableBit CloudDrive settings (check reset databases).
- Wait until that completes.
- Reauthorize your cloud drive.
- It should now mount normally.