coercing to Unicode: need string or buffer, NoneType found when rendering in django admin

Question

I have this error since a long time but can\'t figure it out :

Caught TypeError while rendering: coercing to Unicode: need string or buffer, NoneType found

Answer 1

This error happens when you have a __unicode__ method that is a returning a field that is not entered. Any blank field is None and Python cannot convert None, so you get the error.

In your case, the problem most likely is with the PCE model's __unicode__ method, specifically the field its returning.

You can prevent this by returning a default value:

def __unicode__(self):
   return self.some_field or u'None'