I can't start the quest a deadra's best friend

I tried every entrance to Falkreath to get the quest from the gaurd, didn't work. I tried moving to lod (player.moveto <his ref id>) to ask him about it, doesn't work either. I tried moving to barbas (same as previously, just with his ref id), but apperently he doesn't exist as I got the following error:

"Item '00052535' not found for parameter ObjectReferenceID.

Compiled script not saved!"

Is there any way to fix it and start the quest?