XOOPS Version: 2.0.13.1
Module Name/Version:
PHP Version: 4.4.2
MySQL Version: 4.1.18-standard
Web Server Software: Apache: 1.3.34 (Unix)
Operating System: Linux
Theme you are using: default
Custom template: No
PHP Debug Messages: -message= XOOPS root path not defined
MySQL Debug Messages:
Smarty Debug Messages:
A full description of the issue: see below


Notice [PHP]: Only variable references should be returned by reference in file include/functions.php line 493 -showing several times -message= its just a blank page

Notice [PHP]: Only variables should be assigned by reference in file class/database/mysqldatabase.php line 239 -showing several times -message= XOOPS root path not defined

Notice [PHP]: Only variable references should be returned by reference in file class/database/mysqldatabase.php line 386 -showing several times -message= XOOPS root path not defined

Notice [PHP]: Only variables should be assigned by reference in file include/cp_functions.php line 57 -showing 1 time -message= its just a blank page

Turn off the PHP debugger in Admin panel -> Preferences -> General Settings.
See also here and here and here and here.