I found a strange problem with the new template engine when your server is xampp.

Steps to reproduce:

1. Download xampp (or xampplite/USB) to your windows computer: http://www.apachefriends.org/de/xampp-windows.html#631
2. Install phpBB from current develop branch on github: https://github.com/phpbb/phpbb3/downloads
3. In viewtopic_body.html duplicate the ORs in the template IF by replace

   <!-- IF postrow.U_PM or postrow.U_EMAIL or postrow.U_WWW or postrow.U_MSN or postrow.U_ICQ or postrow.U_YIM or postrow.U_AIM or postrow.U_JABBER -->

   with

   <!-- IF postrow.U_PM or postrow.U_EMAIL or postrow.U_WWW or postrow.U_MSN or postrow.U_ICQ or postrow.U_YIM or postrow.U_AIM or postrow.U_JABBER or postrow.U_EMAIL or postrow.U_WWW or postrow.U_MSN or postrow.U_ICQ or postrow.U_YIM or postrow.U_AIM or postrow.U_JABBER -->

4. Visit the viewtopic.php

As a result your xampp crashes. (After investigation I found out, that it crashes after 8 ORs or more)

NOTE: If you use the same modification (Step 3.) on develop-olympus it displayes the page just fine, which is the reason why I am reporting this!