diff --git a/tools/mega-export-csv.php b/tools/mega-export-csv.php
index 6a233c6..dcc48c9 100755
--- a/tools/mega-export-csv.php
+++ b/tools/mega-export-csv.php
@@ -1,197 +1,204 @@
 #!/usr/bin/php
 <?php
 # boz-mw - Another MediaWiki API framework
 # Copyright (C) 2019, 2020, 2021, 2022 Valerio Bozzolan
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License as published by
 # the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 # GNU Affero General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 
 // exit if not CLI
 $argv or exit( 1 );
 
 // load boz-mw
 require __DIR__ . '/../autoload-with-laser-cannon.php';
 
 define( 'MEDIAWIKI_DATE_FORMAT', 'Y-m-d\TH:i:sZ');
 
 // the number '500' gives to much <This result was truncated because it would otherwise be larger than the limit of 12,582,912 bytes>
 $DEFAULT_LIMIT = 100;
 
 // load configuration
 config_wizard( 'config.php' );
 
 use \web\MediaWikis;
 use \cli\Log;
 
 // all the available wiki UIDs
 $mediawiki_uids = implode( ', ', MediaWikis::allUIDs() );
 
 // register all CLI parameters
 $opts = cli_options()
 	->addValued( 'wiki',  null, "Available wikis: $mediawiki_uids"                     )
 	->addValued( 'limit', null, "Number of revisions for each request", $DEFAULT_LIMIT )
 	->addValued( 'file',  null, "Output filename",                      'export.xml'   )
 	->addFlag(   'help',  'h',  "Show this help and quit"                              );
 
 $messages = [];
 
 // choosen wiki
 $wiki_uid = $opts->get( 'wiki' );
 if( !$wiki_uid ) {
 	$messages[] = "Please specify --wiki=WIKI";
 }
 
 // page titles
 $page_titles = $opts::unnamedArguments();
 if( !$page_titles ) {
 	$messages[] = "Please specify some page titles";
 }
 
 // output filename
 $filename = $opts->get( 'file' );
 if( !$filename ) {
 	// as default assume standard output
 	$filename = 'php://output';
 }
 
 $limit = (int) $opts->get( 'limit' );
 
 // show the help
 $show_help = $opts->get( 'help' );
 if( $show_help ) {
 	$messages = [];
 } else {
 	$show_help = $messages;
 }
 
 if( $show_help ) {
 	echo "Usage:\n {$argv[ 0 ]} --wiki=WIKI --file=export.xml [OPTIONS] Page_title\n";
 	echo "Allowed OPTIONS:\n";
 
 	$opts->printParams();
 
 	foreach( $messages as $msg ) {
 		echo "\nError: $msg";
 	}
 	echo "\n";
 
 	exit( $opts->get( 'help' ) ? 0 : 1 );
 }
 
 // try to open the file
 $file = fopen( $filename, 'w' );
 if( !$file ) {
 	Log::error( "Can't open file '$filename'" );
 	exit( 1 );
 }
 
-// pick the wiki and login
-$wiki = wiki( $wiki_uid )->login();
+// pick the wiki
+$wiki = wiki( $wiki_uid );
+if(!$wiki) {
+	echo "Unrecognized wiki\n";
+	exit( 2 );
+}
+
+// login (if you are a bot you have smaller limitations)
+$wiki->login();
 
 // build the MediaWiki API query
 $requests = $wiki->createQuery( [
 	'action' => 'query',
 	'titles' => $page_titles,
 	'prop'   => 'revisions',
 	'rvprop' => [
 		'ids',
 		'flags',
 		'timestamp',
 		'user',
 		'userid',
 		'size',
 		'slotsize',
 		'sha1',
 		'comment',
 	],
 	'rvslots' => 'main',
 	'rvlimit' => $limit,
 ] );
 
 // total number of revisions
 $total = 0;
 
 $n_requests = 1;
 
 fputcsv( $file, [
 	"Date",
 	"Time",
 	"Dimension",
 	"User ID",
 	"User name",
 	"Comment",
 ] );
 
 // do not print to the out
 foreach( $requests as $request ) {
 
 	// show a kind of progress
 	Log::info( sprintf(
 		"processing request %d (continuing from $total revisions)",
 		$n_requests++
 	) );
 
 	$response_warning_shown = false;
 
 	foreach( $request->query->pages as $page ) {
 
 		if( isset( $page->missing ) ) {
 			Log::error( "Page '{$page->title}' is missing" );
 			exit( 1 );
 		}
 
 		$alert_much_revisions = true;
 		foreach( $page->revisions as $i => $revision ) {
 
 			// avoid nonsense revisions
 			if( empty( $revision->comment ) ) {
 				$count = count( $page->revisions );
 				if( $count !== $limit && !$response_warning_shown ) {
 					Log::warn( "response with $count revisions instead of $limit: consider to lower your limit (ignore if you see this just once)" );
 					$response_warning_shown = true;
 				}
 			}
 
 			$total++;
 
 			foreach( $revision->slots as $slot ) {
 
 				$safe_user    = $revision->user;
 				$safe_userid  = $revision->userid;
 				$size         = $revision->size;
 				$timestamp    = $revision->timestamp;
 				$comment      = $revision->comment;
 
 				$timestamp_date = DateTime::createFromFormat( MEDIAWIKI_DATE_FORMAT, $timestamp );
 				$timestamp_ymd = $timestamp_date->format( 'Y-m-d' );
 				$timestamp_his = $timestamp_date->format( 'H:i:s' );
 
 				fputcsv( $file, [
 					$timestamp_ymd,
 					$timestamp_his,
 					$size,
 					$safe_user,
 					$safe_userid,
 					$comment,
 				] );
 			}
 		}
 	}
 }
 
 Log::info( sprintf(
 	"you mega-exported %d revisions!",
 	$total
 ) );
 
 fclose( $file );