Index: /branches/release-35/lib/MT/Upgrade.pm
===================================================================
--- /branches/release-35/lib/MT/Upgrade.pm (revision 1938)
+++ /branches/release-35/lib/MT/Upgrade.pm (revision 1955)
@@ -936,4 +936,7 @@
         return 0;
     }
+    if ($plugindata) {
+        return 0;
+    }
 
     my $offset = int($param{offset} || 0);
@@ -972,5 +975,5 @@
 
     my $sth = $dbh->prepare($sql)
-        or return $self->error($dbh->errstr || $DBI::errstr);
+        or return 0; # ignore this operation if _meta column doesn't exist
     $sth->execute
         or return $self->error($dbh->errstr || $DBI::errstr);