in reply to Toolkit Template undef error debugging

Something in my data has changed, but I'm not sure what, or where to look.

The obvious place to look is your revision control system. It allows you to go back to previous versions, and compare differences.

If you don't use one, start using one now - it's a very useful debugging tool, takes the fear of breaking stuff when you change things, and is also otherwise generally useful.

Perl 6 - links to (nearly) everything that is Perl 6.