Fixes #678: Server error on device import specifying an invalid device type

netbox/dcim/models.py

@@ -852,8 +852,7 @@ class Device(CreatedUpdatedModel, CustomFieldModel):
                 'face': "Must specify rack face when defining rack position."
             })
 
-        if self.device_type:
-
+        try:
             # Child devices cannot be assigned to a rack face/unit
             if self.device_type.is_child_device and self.face is not None:
                 raise ValidationError({
@@ -880,6 +879,9 @@ class Device(CreatedUpdatedModel, CustomFieldModel):
             except Rack.DoesNotExist:
                 pass
 
+        except DeviceType.DoesNotExist:
+            pass
+
     def save(self, *args, **kwargs):
 
         is_new = not bool(self.pk)