Beta Test 2.3.0.0_b1 Error

it work with the old site in sub-directory however it seems the install scripts on the new version uses quite a lot of paths,
any suggestions?

/home/amillio8/public_html/Demo/
/home/amillio8/public_html/Demo/system/
/home/amillio8/public_html/Demo/index.php
Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /home/amillio8/public_html/Demo/index.php:29) in /home/amillio8/public_html/Demo/system/library/session.php on line 30

Warning: Cannot modify header information - headers already sent by (output started at /home/amillio8/public_html/Demo/index.php:29) in /home/amillio8/public_html/Demo/system/library/session.php on line 50

Warning: Cannot modify header information - headers already sent by (output started at /home/amillio8/public_html/Demo/index.php:29) in /home/amillio8/public_html/Demo/system/library/response.php on line 12

The full server path is not something that has been used as a new feature since this release, this tactic is actually pretty old-based with Opencart and many other platforms. The full server path is captured from the opencart installation intentionally in order to store them into the config.php and admin/config.php files. However, I would not recommend to post your full true server path on the forum as I would suggest to replace your second folders with xxxxx for security purposes.

I narrowed down the errors to the following, any suggestions?

Fatal error: Call to undefined method Loader::library() in /home/amillio8/public_html/Demo/system/framework.php on line 86

I also encountered this problem and reported it on another topic a while back regarding the use of:
instead of the:
function. If you installed an extension, simply disable it and see if the error message still appears. If so, track down the one or many $this->load->library lines from those extensions and see if you can locate their paths and filenames and post them each on your next reply.