KeyError: 'prodlot_id'

while update the stock value from update button i got this trace back :

Client Traceback (most recent call last):
  File "/home/amit/OpenERP/web/trunk/addons/web/common/http.py", line 175, in dispatch
    response["result"] = method(controller, self, **self.params)
  File "/home/amit/OpenERP/web/trunk/addons/web/controllers/main.py", line 1060, in load
    fields_view = self.fields_view_get(req, model, view_id, 'search')
  File "/home/amit/OpenERP/web/trunk/addons/web/controllers/main.py", line 878, in fields_view_get
    fvg = Model.fields_view_get(view_id, view_type, context, toolbar, submenu)
  File "/home/amit/OpenERP/web/trunk/addons/web/common/openerplib/main.py", line 430, in proxy
    *args)
  File "/home/amit/OpenERP/web/trunk/addons/web/common/openerplib/main.py", line 306, in proxy
    result = self.connector.send(self.service_name, method, *args)
  File "/home/amit/OpenERP/web/trunk/addons/web/common/openerplib/main.py", line 276, in send
    raise fault

Server Traceback (most recent call last):
  File "/home/amit/OpenERP/web/trunk/addons/web/common/openerplib/main.py", line 257, in send
    result = openerp.netsvc.dispatch_rpc(service_name, method, args)
  File "/home/amit/OpenERP/server/trunk/openerp/netsvc.py", line 325, in dispatch_rpc
    result = ExportService.getService(service_name).dispatch(method, params)
  File "/home/amit/OpenERP/server/trunk/openerp/service/web_services.py", line 580, in dispatch
    res = fn(db, uid, *params)
  File "/home/amit/OpenERP/server/trunk/openerp/osv/osv.py", line 120, in wrapper
    return f(self, dbname, *args, **kwargs)
  File "/home/amit/OpenERP/server/trunk/openerp/osv/osv.py", line 172, in execute
    res = self.execute_cr(cr, uid, obj, method, *args, **kw)
  File "/home/amit/OpenERP/server/trunk/openerp/osv/osv.py", line 163, in execute_cr
    return getattr(object, method)(cr, uid, *args, **kw)
  File "/home/amit/OpenERP/addons/trunk/stock/wizard/stock_change_product_qty.py", line 47, in fields_view_get
    result['fields']['prodlot_id']['required'] = False
KeyError: 'prodlot_id'

I have also attach video for that

Thanks,
Amit