Hi Simon,
Seems like a Linux guest environment is missing. You can follow the below steps as provided in our public issue tracker which might help you resolve the issue.
Stop the instance
Create a snapshot of the instance
Create a new disk from the snapshot and
Attach the disk to another new instance
I hope this helps.
1. Generate new instances and log into them.Works fine.
2. Make a clone of the system, but this only copies the structure of the system and not the files. - Logs in but no files.
3. I have tried recreating an instance based off a snapshot of the drive I cant access.I get the same message as before.
4. I have tried recreating an instance based off an image i have derived from the drive i cant access. I get the same message as before.