Added messages to the part of processing, which is useful when an unknown error is encountered. Could prove useful while debugging.

lib/Selenium/Remote/Driver.pm

@@ -215,6 +215,8 @@ sub _execute_command {
                    if(ref($resp->{cmd_return}) eq 'HASH') {
                      $msg .= ": $resp->{cmd_return}->{error}->{msg}"
                        if $resp->{cmd_return}->{error}->{msg};
+                     $msg .= ": $resp->{cmd_return}->{message}"
+                       if $resp->{cmd_return}->{message};
                    } else {
                      $msg .= ": $resp->{cmd_return}";
                    }

lib/Selenium/Remote/ErrorHandler.pm

@@ -111,6 +111,7 @@ sub process_error {
     my $ret;
     $ret->{'stackTrace'} = $resp->{'value'}->{'stackTrace'};
     $ret->{'error'} = $self->STATUS_CODE->{$resp->{'status'}};
+    $ret->{'message'} = $resp->{'value'}->{'message'};
 
     return $ret;
 }