It depends how you have transferred the files and database. Through Akeeba or any third party extension or manually. If you transferred manually then there is less chance of change in public $dbprefix = 'jos83_';
present in configuration file, as you need to change just the database user, database name and hostname in configuration.php file.
Suppose you did through Akeeba then it will ask for a new prefix during site restoration. Suppose you did through Akeeba and still it doesnt work then your session table may be damaged. And if session table is damaged Joomla wont load. You have to manully delete the table and recreate it in phpmyadmin using this sql command
DROP TABLE IF EXISTS `resoninr_session`;
CREATE TABLE IF NOT EXISTS `resoninr_session` (
`username` varchar(150) default '',
`time` varchar(14) default '',
`session_id` varchar(200) NOT NULL default '0',
`guest` tinyint(4) default '1',
`userid` int(11) default '0',
`usertype` varchar(50) default '',
`gid` tinyint(3) unsigned NOT NULL default '0',
`client_id` tinyint(3) unsigned NOT NULL default '0',
`data` longtext,
PRIMARY KEY (`session_id`(64)),
KEY `whosonline` (`guest`,`usertype`),
KEY `userid` (`userid`),
KEY `time` (`time`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
Some helpful links
- http://forum.joomla.org/viewtopic.php?t=362525
- why does joomla 2.5 session table corrupt?
- https://www.ostraining.com/blog/joomla/joomla-session-crashed/