[Zope] Debugging errors?

[Guy Jacobson]

I am getting a mysterious error when I try to add a discussion to Squishdot:

   Error Type: TypeError
   Error Value: not enough arguments; expected 2, got 1

I have no idea where in the code of Zope or Squishdot this comes from.
How would I go about debugging it?  I checked the logs and there is nothing
in them about this error.

Thank you,

Guy.