Hi I'm trying to write a standard_error_message page in ZPT and attach it to my class. In my class definition I have: standard_error_message = PageTemplateFile('html/error_page.html', globals()) and manage_master = PageTemplateFile('html/master_page.html', globals()) in error_page.html I have: <p tal:content="exists:container/manage_master" /> Now, this returns true: http://localhost:8080/sites/myClassInstance/standard_error_message but this returns false: http://localhost:8080/sites/myClassInstance/some_nonexistent_page There are also other methods that are found when calling standard_error_message explicitly, but not when it's called as a result of an error. What am I missing about how standard_error_message is called? TIA Felix.