During my work with personal computers and servers I experienced a lot of problems. So, whenever I have a problem I try to add the solution here. Due to the mass of problems, I am sure the list is going to grow fast 😏.
Thanks to all the other guys in the www helping also with solutions to the different kind of problems.
As soon as the basic installation of Joomla has been completed, the setup can be carried out. I had the following problem: the installer always stopped halfway without warning. Ultimately, it was because of the PHP version. Only after I changed the server configuration to PHP7.2 did the installation work properly. After the installation I was able to switch PHP back to 7.4. The problem was caused by the Apache mod-evasive module. For one thing, there were many 403 errors in the operation of Joomla and new installations could not be set up. For this reason, I first switched off this module:
Log in via SSH and cd to the main directory of your website, e.g .:
sudo -s cd /var/www/<Your Directory>/web
While upgrading my server, most probably while doing the upgrade to Ubuntu 20.04 Focal, mod-evasive got installed and enabled. It didn't effect the configured websites, except sometimes for a couple of seconds I received 403 errors. But finally everything continued working. The problem started, after adding a new website and trying to install a new Joomla platform. The installation process of Joomla stopped on the very last step without any error message on the screen.
It is not very annoying for a visitor of your site, but a lot of crawlers are loorking for the meta key:
<meta name="generator" content="Joomla! - Open Source Content Management" />
Unfortunately some bad guys looking for Joomla websites to take advantage of any possible security vulnerabilities.
By default OpenVPN runs on port 1194. This is quite nice, but often this port is not open in the firewalls. Therefor the OpenVPN server is unreachable. It also has advantages to run SSH on port 443. You may have fewer fake logins on the SSH server. In addition, port 22, or even any custom port such as 2020, is blocked by firewalls in most cases as well. If you simply put everything on port 443, this may not work, since Apache is already active for the SSL websites. And that's where SSLH jumps in.