Is your forum running on FreeBSD?
On FreeBSD, this library is NOT included automatically. It must be manually installed. This can be done with the following command:
source:
https://www.php.net/manual/en/ctype.installation.phpfurther reading here:
https://www.php.net/manual/en/intro.ctype.phpand here:
https://www.php.net/manual/en/book.ctype.phpin your forum's PHP Info page, you should see under ther
ctype section,