Got the same error on Debian 8.2
Also in "Multiple Row In-Line Editing / User Action / Join Example" Example:
Something went wrong...
Most likely the ajax url is incorrect.
If the ajax url is correct check your apache error log file for more information.
-> Error Log:
[Tue Jan 26 13:46:09.557850 2016] [:error] [pid 30556] [client <censored>:49996] PHP Fatal error: Uncaught exception 'Exception' with message 'An error occurred in script /var/www/<censored>/php/AjaxTableEditor.php on line 2830: <br /><br />There was an error executing the following query: <br />select `login_info`.`id`, \nconcat(emp.first_name,' ',emp.last_name) as `employee_id`, \n`login_info`.`login`, \n`login_info`.`password`, \n`login_info`.`account_type`\nfrom login_info\n left join `employees` as `employees` on `login_info`.`employee_id` = `employees`.`id`\n order by `employee_id` asc limit 0, 20<br /><br />PDO error:<br /> "SQLSTATE[42S22]: Column not found: 1054 Unknown column 'emp.first_name' in 'field list'" on line: 346' in /var/www/<censored>/Common.php:26\nStack trace:\n#0 [internal function]: Common->logError('<br /><br />Th...', '/var/www/<censored>...', 2830, 'mate1_')\n#1 /var/www/<censored>/php/AjaxTableEditor.php(361): call_user_func(Array, '<br /><br />Th...', '/var/www/<censored>...', 2830, 'mate1_')\n#2 /var/www/<censored>/php/AjaxTableEditor.php(2830): AjaxTableEditor->doQuery('select `login_i...' in /var/www/<censored>/Common.php on line 26, referer:
http://<censored>/mate/JoinExample.php