after upgrade 3.5.2

[uaeboy7127]

after upgading 3.5.2

i cant use my form


this is the eroor



Warning: Invalid argument supplied for foreach() in /includes/class_core.php on line 2736




Unable to add cookies, header already sent.
File: /home/jaware7/public_html/352/includes/class_core.php
Line: 2957


i use the tools.php to solv the problem

but no use

till me how to solv this problem please

also i change all files for forum