There is an issue within postbit template of your theme - most likely an unclosed tag or HTML tags in attribute like alt/title. Find and change it if you are able to, revert the template in Options or post it here so someone can correct it.
Well PM Arbaz for help. He is the one who made the theme so you can report this as bug. Else post your postbit template here.
I've sent the OP a PM. Even though I can see posts and didn't find any bugs on localhost, I'll still double check with the OP just in-case they did any modification affecting the postbit template.
Edited
Please download and install the template conditionals plugin otherwise this plugin will be buggy. It's also stated in the download information on the mods.
Plugin:
http://mybbhacks.zingaburga.com/showthread.php?tid=464
2nd Edit
I found the issue. I left an extra > in the postbit template. I've fixed the issue and updated the themes on the mod. For OP, simply go to ACP>Templates & Styles>Templates>Vicious>Postbit Templates>Postbit>Options>Revert to Original or you can wait for the updated version.
Thanks for bringing up the issue
