Dear helpers,

I am using v17 and facing below issue and have no clue to resolve it. I have to comment the second 'inherit'.

Error: ValueError: The _name attribute MrpWorkcenter is not valid.

code:

class MrpWorkcenter(models.Model):
    _inherit = 'mrp.workcenter'
    _inherit = [ 'mail.thread',
                'mail.activity.mixin',
                ]  # add a chatter

if I set the following, the ERROR becomes 

TypeError: Many2many fields MrpWorkcenter1.alternative_workcenter_ids and mrp.workcenter.alternative_workcenter_ids use the same table and columns

_inherit = ['mrp.workcenter', 'mail.thread', 'mail.activity.mixin',]