Issue Clean Debian 8 / Plesk Onxy install, missing suexec?

[Konggal]

Been running into the

Server Error
500
Internal Server Error

alot since i reinstalled everything on a clean slate

reinstalled server, did a apt update and upgrade, installed plesk with plesk installer, setup a few sites and databases and now i see some of my pages are giving me that error 500
when looking in the logs i found

(104)Connection reset by peer: mod_fcgid: error reading data from FastCGI server, referer: https://kb.tluc.me/?a=admin_zkbfetch

End of script output before headers: index.php, referer: https://kb.tluc.me/?a=admin_zkbfetch

After looking around on google i finally finds error reading data from FastCGI server which looks like being the issue i have
but the very first command

 cp -p /usr/sbin/suexec /usr/sbin/suexec.dist

Fails because i don't have a suexec?
Tried to do a find on the server and looks like there isn't a suexec at all? wouldn't that be installed and setup together with plesk?

Tried to skip to step 2 and copy it over which went fine but then the chown complained since there is no apache group?
chown: invalid group: ‘root:apache’

have plesk installer failed to correctly setup even that there was no errors when installing or what could be the issue?

 

[IgorG]

The first command in KB article is for CentOS, but you have Debian if I'm not mistaken.

 

[Konggal]

Hay @IgorG
Yep running Debian 8, had the guy who made the KB article update it for all OS's but even with that fix it doesn't seem to fix the issue it self :/