A MARKUP-ERROR rule is trying to write to the #MARKUP-PARSER stream.
          #7901   Run-time warning
          A MARKUP-ERROR rule is trying to write to the #MARKUP-PARSER stream.
Additional Information
 The data written will be ignored.
Explanation
 In past versions of OmniMark, markup-error rules were able to write to the #markup-parser
        stream and thus modify the parsed input. This functionality has been disabled by default, due to the performance
        issues it led to. Contact Stilo for further information.