Slim v3 Error withJSON and ß [SOLVED]

when i try to show my json code containing ß character i got

Slim Application Errorbody{margin:0;padding:30px;font:12px/1.5 Helvetica,Arial,Verdana,sans-serif;}h1{margin:0;font-size:48px;font-weight:normal;line-height:48px;}strong{display:inline-block;width:65px;}

Slim Application Error

A website error has occurred. Sorry for the temporary inconvenience.

as response. Any idea or solution to fixx that ?

If you turn on ‘displayErrorDetails’ does it give any additional information?

i found out that i had a writing mistake. i wrote utf-8 but it had to be utf8 (Mysql Charset)