There was a problem with your page.

shocked Ren That's why you see this custom error page ;-)

Page "/test/testerror_cust.y" caused an error: integer division or modulo by zero (type=)

Traceback (innermost last):

   File "/Users/irmen/www_snakelets/snakeserver/YpageEngine.py", line 255, in createOutput
    self.create(out,_request,_response)
  File "<Ypage_code_of_testerror_cust>", line 19, in create

ZeroDivisionError: integer division or modulo by zero
You can make your error page more interesting than this, of course, if you like.
This page generates an error. And has a custom error page.