קבצי מסד הנתונים אינם תואמים לשרת (מעודכן בתוך Linode)

It is fair to say that I don’t really know what I am doing.
I have created a new VPS running Ubunto 24.0.1 LTS and am up to the instruction to

rsync -rvz example.com:/var/discourse /var

Due to my failed upgrade, example.com gives 502 bad gateway.
I am on a learning curve trying to figure out how to grant access anyway.