id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
18146	Exception during form validation	richard.o.dodd@…	nobody	"An exception with unhelpful message occurs when the following model is validated

{{{
from django.db import models

class a(models.Model):
    pass

class b(models.Model):
    c_a = models.ManyToManyField(a)
}}}

Maybe it would be more neat to return an error in the validation.
Haven't checked in newer versions, could someone try to replicate it.
"	Bug	closed	Database layer (models, ORM)	1.3	Normal	needsinfo	model, manage, validation		Unreviewed	0	0	0	0	0	0