mb_internal_encoding("UTF-8");

[Kola13]

Get this error:

PHP Fatal error: Uncaught Error: Call to undefined function mb_internal_encoding() in /usr/local/bin/h-m-m:17
Stack trace:
#0 {main}
thrown in /usr/local/bin/h-m-m on line 17

I'm a newb, but I think it has to do with defining PHP to work with line 17, but I'm not too sure why.

mb_internal_encoding("UTF-8");

Thanks

[Nader K. Rad]

You're using an old version of php. Install mbstring to solve the problem; e.g., sudo apt install php7.2-mbstring in Ubutu (replace 7.2 with the actual php version if it's different).