This is a common problem I find when I do a new Apache 2 install on Ubuntu. There is a simple solution to stop seeing this message. Edit httpd.conf, type this command in a terminal:

sudo gedit /etc/apache2/httpd.conf

Add this line at the end of the file

ServerName myserver

You can replace myserver with whatever name you want to use for your server.

If that doesn’t completely fix the problem try adding the same line:

ServerName myserver

At the end of /etc/apache2/apache2.conf

That should do it.

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