No ruleset name as specified where one was needed
This error happens if no ruleset is specified when a plugin needs one to function properly. This usually happens with omruleset, which needs to have the name of the ruleset to submit to. Note that in recent versions of rsyslog, omruleset has been superseded by the better "call" statement.
Some versions of mmnormalize also emit this error. In that case, what actually is missing is the normalization (sample) database.