Why does the server give error #500 when loading the admin panel in FreePBX?

Question

Asterisk

Good day to all! I installed everything according to the manual , there were no problems at the compilation stage. But I could not log in http://my-ip/admin . Server gives 500 error.
Judging by the logs, the problem is in the session.

PHP Fatal error: Class 'FreePBX' not found in /var/www/html/admin/config.php on line 126

126 line -

$sessionTimeOut = FreePBX::Config()→get('SESSION_TIMEOUT');

What the logs say:

[pid 1171] [client 172.16.12.26:55847] PHP Warning: Unknown: open(/var/lib/php/sessions/sess_h1behae5j0jdcar1uv1p9grbt6, O_RDWR) failed: Permission denied (13) in Unknown on line 0

[pid 1171] [client 172.16.12.26:55847] PHP Warning: Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/var/lib/php/sessions$

Problem in the delegation of rights? I set the rights to the sessions 777 directory, but it did not give any result. (although that's not the point).
Tell me, please, from what to build on? Problem with permissions or something else?
Thank you all in advance for your replies!

Answer 1

You do not have access to the session file, see the rights to the /var/lib/php/sessions directory, who is the owner and from whom you write and read this directory. And with what rights are session files created?
This is more of a Web problem than Asterisk