An Error is appearing.. Please Help

I a Website in OpenCart with 2 Language supports.
I recently made a minor change in HTML of Welcome Module in chinese Language Modules.
and it is showing this
In Admin Panel..
Notice: unserialize() [function.unserialize]: Error at offset 65345 of 65535 bytes in /home/ysycomsg/public_html/admin/index.php on line 51

In Website
Notice: unserialize() [function.unserialize]: Error at offset 65345 of 65535 bytes in /home/ysycomsg/public_html/index.php on line 67

And All Contents are not showing of Welcome Page or Home Page..
Please Help Me how to undo my last action or How to fix this issue.