Warning: oci_connect(): ORA-12543: TNS: Ziel-Host ist nicht erreichbar in /var/www/html/mdl/dbconn.php on line 180

Fatal error: Uncaught TypeError: oci_parse(): Argument #1 ($connection) must be of type resource, bool given in /var/www/html/mdl/dbconn.php:185 Stack trace: #0 /var/www/html/mdl/dbconn.php(185): oci_parse() #1 /var/www/html/index.php(6): include('...') #2 {main} thrown in /var/www/html/mdl/dbconn.php on line 185