Error in my website

Hello im having this error since March i just saw my error log and found this error how to fix this

[14-Apr-2018 18:58:30 America/New_York] PHP Fatal error: Uncaught Error: Call to a member function processTplStep() on null in /home/t***/public_html/tmp/compile/%%AE^AEB^AEBD0B1C%%add_listing.tpl.php:34
Stack trace:
#0 /home/t***/public_html/libs/smarty/Smarty.class.php(1884): include()
#1 /home/t***/public_html/includes/classes/rlSmarty.class.php(81): Smarty->_smarty_include(Array)
#2 /home/t***/public_html/tmp/compile/%%A1^A1E^A1EADC17%%content.tpl.php(144): rlSmarty->_smarty_include(Array)
#3 /home/t***/public_html/libs/smarty/Smarty.class.php(1261): include('/home/-0-0-0/...')
#4 /home/t***/public_html/includes/classes/rlSmarty.class.php(68): Smarty->fetch('content.tpl', NULL, NULL, true)
#5 /home/t***/public_html/libs/smarty/Smarty.class.php(1108): rlSmarty->fetch('content.tpl', NULL, NULL, true)
#6 /home/t***/public_html/index.php(353): Smarty->display('content.tpl')
#7 {main}
thrown in /home/t***/public_html/tmp/compile/%%AE^AEB^AEBD0B1C%%add_listing.tpl.php on line 34