Avoid Template Errors
Many forum admins faced error with templates when modifying forum template.
phpBB : Critical Error
Could not open template config file
Line : XXX
File : functions.php
Here are some tips to avoid template error
Login to admin and install template with
Admin > Styles Admin > Add link
Do you change template for all users untill you test the template and make sure it works. To do this, you need to login as another user. Click on Profile link on top. Select new style from "Board Style" drop down box. Scroll down and click submit button.
Now the template for the user is changed. Check if everything works. If everything works fine, you can set the skin as default for all users or try another skin.
Set Template as Default
Login to forum as Administrator. Click on "Go to Administration Panel" link and go to Admin area.
Admin > General Admin > Configuration
Select the template you need in "Default Style" drop down box. Also make "Override user style" option box set to "Yes".