I was able to jiggle the old USB until it finally worked, so hopefully it holds up until the sale when I can more easily transfer the config.
As I've configured all my shares and access, I really didn't want to go through reconfiguring it all.
As described in the title, I'd used an old USB that started failing. I was able to recover the config folder, but Unraid is refusing to let me continue the trial on the new USB.
Is there a stop-gap solution until the Cyber sale starts?