Setup will now attempt to setup the database: Creating connection to the database: OK! Selecting database `122_andreleubner`: OK! Creating database tables: OK! Writing configuration file: OK! Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /home/www/andre-leubner.de/htdocs/manager/processors/cache_sync.class.processor.php on line 78 Warning: mysql_fetch_row(): supplied argument is not a valid MySQL result resource in /home/www/andre-leubner.de/htdocs/manager/processors/cache_sync.class.processor.php on line 81 Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /home/www/andre-leubner.de/htdocs/manager/processors/cache_sync.class.processor.php on line 93 Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /home/www/andre-leubner.de/htdocs/manager/processors/cache_sync.class.processor.php on line 111 Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /home/www/andre-leubner.de/htdocs/manager/processors/cache_sync.class.processor.php on line 121 Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /home/www/andre-leubner.de/htdocs/manager/processors/cache_sync.class.processor.php on line 133 Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /home/www/andre-leubner.de/htdocs/manager/processors/cache_sync.class.processor.php on line 149 Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /home/www/andre-leubner.de/htdocs/manager/processors/cache_sync.class.processor.php on line 169 Couldn't determine next publish event! Warning: mysql_fetch_assoc(): supplied argument is not a valid MySQL result resource in /home/www/andre-leubner.de/htdocs/manager/processors/cache_sync.class.processor.php on line 215 Couldn't determine next unpublish event! Warning: mysql_fetch_assoc(): supplied argument is not a valid MySQL result resource in /home/www/andre-leubner.de/htdocs/manager/processors/cache_sync.class.processor.php on line 225 Installation was successful!

Can you see if the tables exist via phpMyAdmin.
the table prefix was false, now with prefix modx_ it´s no problem...