Hi,

when I use the quick search option in start screen, I get this error.
Someone any idea ?

Fatal error: Uncaught Error: Call to undefined function mb_strlen() in /var/www/html/include/functions_search.inc.php:919 Stack trace: #0 /var/www/html/include/functions_search.inc.php(1047): qsearch_get_text_token_search_sql(Object(QSingleToken), Array) #1 /var/www/html/include/functions_search.inc.php(1383): qsearch_get_tags(Object(QExpression), Object(QResults)) #2 /var/www/html/include/functions_search.inc.php(1301): get_quick_search_results_no_cache('1', Array) #3 /var/www/html/include/functions_search.inc.php(1474): get_quick_search_results('1', Array) #4 /var/www/html/include/section_init.inc.php(350): get_search_results('3', NULL) #5 /var/www/html/index.php(12): include('/var/www/html/i...') #6 {main} thrown in /var/www/html/include/functions_search.inc.php on line 919

Piwigo 2.10.2
Betriebssystem: Linux
PHP: 7.2.24-0ubuntu0.18.04.4
MySQL: 5.7.30-0ubuntu0.18.04.1
Grafikbibliothek: GD 2.2.5