Can you update the MM package without the mattermost-advisor user present by default?
It cannot be removed manually via the CLI as in the last post of the article ;-/
from RO issues for the log, to inability to open the DB connection, the CLI doesn't seem to work.
the CLI doesn't seem to work.
Generally the CLI works just as described in the Cloudron manual: https://docs.cloudron.io/apps/mattermost/#command-line-tool
But looking at https://mattermost.atlassian.net/browse/MM-34893 (which was linked to in the initial post you linked) it looks like the advisor is not active at all in versions after 5.35 (Cloudron is at 5.36.1 it seems).