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:

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sudo gedit /etc/apache2/httpd.conf

Add this line at the end of the file

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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:

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ServerName myserver

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

That should do it.

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