Demo Don't Work

Hi,
I tried to use the demo today:

Warning: main(./modules/installed_modules.php) [function.main]: failed to open stream: No such file or directory in /home/frontacc/public_html/acc2/applications/customers.php on line 3

Warning: main() [function.include]: Failed opening './modules/installed_modules.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/frontacc/public_html/acc2/applications/customers.php on line 3

Warning: main(./modules/installed_modules.php) [function.main]: failed to open stream: No such file or directory in /home/frontacc/public_html/acc2/applications/suppliers.php on line 3

Warning: main() [function.include]: Failed opening './modules/installed_modules.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/frontacc/public_html/acc2/applications/suppliers.php on line 3

Warning: main(./modules/installed_modules.php) [function.main]: failed to open stream: No such file or directory in /home/frontacc/public_html/acc2/applications/inventory.php on line 3

Warning: main() [function.include]: Failed opening './modules/installed_modules.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/frontacc/public_html/acc2/applications/inventory.php on line 3

Warning: main(./modules/installed_modules.php) [function.main]: failed to open stream: No such file or directory in /home/frontacc/public_html/acc2/applications/manufacturing.php on line 3

Warning: main() [function.include]: Failed opening './modules/installed_modules.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/frontacc/public_html/acc2/applications/manufacturing.php on line 3

Warning: main(./modules/installed_modules.php) [function.main]: failed to open stream: No such file or directory in /home/frontacc/public_html/acc2/applications/dimensions.php on line 3

Warning: main() [function.include]: Failed opening './modules/installed_modules.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/frontacc/public_html/acc2/applications/dimensions.php on line 3

Warning: main(./modules/installed_modules.php) [function.main]: failed to open stream: No such file or directory in /home/frontacc/public_html/acc2/applications/generalledger.php on line 3

Warning: main() [function.include]: Failed opening './modules/installed_modules.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/frontacc/public_html/acc2/applications/generalledger.php on line 3

Warning: main(./modules/installed_modules.php) [function.main]: failed to open stream: No such file or directory in /home/frontacc/public_html/acc2/applications/setup.php on line 3

Warning: main() [function.include]: Failed opening './modules/installed_modules.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/frontacc/public_html/acc2/applications/setup.php on line 3

Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at /home/frontacc/public_html/acc2/applications/customers.php:3) in /home/frontacc/public_html/acc2/includes/lang/language.php on line 75

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home/frontacc/public_html/acc2/applications/customers.php:3) in /home/frontacc/public_html/acc2/includes/lang/language.php on line 75

Warning: Cannot modify header information - headers already sent by (output started at /home/frontacc/public_html/acc2/applications/customers.php:3) in /home/frontacc/public_html/acc2/includes/lang/language.php on line 77