My web provider writes that I am using an outdated and slow version of PHP on my website, and they recommend that I update PHP, by removing the following line from the .htaccess file on my web space: AddType application/x-httpd-php56 .php.
I'm using CMSimple_XH 1.6.10 with a number of plugins. Is there a risk in doing this?
PHP
Re: PHP
Yes unfortunately, the website will probably stop working/start with a fatal error message.
See also the thread here.
You can find upgrade instructions here: To upgrade your website to CMSimple_XH 1.7.0, do the following
This should also work for CMSimple_XH 1.7.6.
„Bevor du den Pfeil der Wahrheit abschießt, tauche die Spitze in Honig!“ 
Ludwig's XH-Templates for MultiPage & OnePage
Ludwig's XH-Templates for MultiPage & OnePageRe: PHP
I also would recommend definitely the upgrade the whole website to 1.7.6 and then update also all possible plugins and the actual PHP (at least 7.x.). The procedure is not very complicated and you can find many posts about "how to" here in forum..
CMSimple.sk
It's no shame to ask for an answer if all efforts failed.
But it's awful to ask without any effort to find the answer yourself.
It's no shame to ask for an answer if all efforts failed.
But it's awful to ask without any effort to find the answer yourself.