Greetings, I am trying to install XOOPS 1.3.10 but I get an error when I go to my website. How do I install xoops, I need this older version cause I am using an older theme. I get the following error...

Warning: main(/path/to/xoops/directory/include/common.php): failed to open stream: No such file or directory in /var/www/localhost/htdocs/mmorpg/mainfile.php on line 60

Warning: main(): Failed opening '/path/to/xoops/directory/include/common.php' for inclusion (include_path='.:/usr/share/php4:/usr/share/php') in /var/www/localhost/htdocs/mmorpg/mainfile.php on line 60

Fatal error: Call to undefined function: xoops_header() in /var/www/localhost/htdocs/mmorpg/header.php on line 23

Aside from the fact that older versions of XOOPS lack the security of current ones and will also not necessarily be compatablle with a range of modules...the errors can be searched here in FAQ and the installation documentation is at the documentation site linked on the left. What versions of php/mysql are you attempting to use with this old version and finally is this a local install (sounds like it with the references to a 'www' folder...

The main thing to look for is to ensure you have your paths correct...If I am correct they are affecting your mainfile. Physical and virtual path information can be found here

You can search for undefined function errors as well.

You really should engage in best practice and install the current version of XOOPS and then seek to have your theme updated to work rather than install XOOPS to match your theme.