Error 22023

SR005: Function http_sys_find_best_sparql_accept needs a string or NULL as argument 1, not an arg of type INTEGER (189)
in
http_sys_find_best_sparql_accept:(BIF),
        __01 => 0,
        __02 => 1,
        __03 => 0,
DB.DBA.SPARQL_RESULTS_WRITE([executable]/sparql_io.sql:2059),
         ses => (STRING_SESSION value, tag 185),
       metas => (ARRAY_OF_POINTER value, tag 193),
        rset => (ARRAY_OF_POINTER value, tag 193),
      accept => 0,
       flags => 1,
      status => NULL,
sioc.DBA.ods_obj_describe:106,
         iri => 'http://kingsley.idehen.net/dataspace/person#this',
         fmt => 'text/turtle',
           p => 0,
DB.DBA.RDFData_DAV_RES_CONTENT([executable]/DET_RDFData.sql:606),
          id => (ARRAY_OF_POINTER value, tag 193),
     content => (STRING_SESSION value, tag 185),
        type => 'text/turtle',
  content_mode => 1,
DB.DBA.DAV_RES_CONTENT_INT([executable]/dav_api.sql:5876),
          id => (ARRAY_OF_POINTER value, tag 193),
     content => (STRING_SESSION value, tag 185),
        type => 'text/turtle',
  content_mode => 1,
      extern => 0,
  auth_uname => NULL,
    auth_pwd => NULL,
WS.WS.GET([executable]/dav.sql:2995),
        path => (ARRAY_OF_POINTER value, tag 193),
      params => (ARRAY_OF_POINTER value, tag 193),
       lines => (ARRAY_OF_POINTER value, tag 193)