Page will not display with an array (using treeview)

[eluser]JanDoToDo[/eluser]
And the problem is (as you can see i have commented out the line in the post directly above) if i uncomment this line, the page goes straight to "page cannot be displayed" and if i leave it commented out, the page loads fine.

So i thought maybe it is to do with the data in the array, but it is populated in exactly the same way as the others and i can vardump it in the controller and the data is fine. Is there a max limit to a page size or something? What would cause it to jump to "page cannot be displayed" instead of some kind of error message??