Hello,

I have a big problem with POS today.

A user has changed session before that all tickets from the old session are synchronized. What currently shows me an error.

Please find a screenshot here: http://imgur.com/a/ecyqK

Please help me to fix this issue.

Traceback (most recent call last):
  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\http.py", line 648, in _handle_exception  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\http.py", line 685, in dispatch  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\http.py", line 321, in _call_function  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\service\model.py", line 118, in wrapper  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\http.py", line 314, in checked_call  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\http.py", line 964, in __call__  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\http.py", line 514, in response_wrap  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\openerp\addons\web\controllers\main.py", line 903, in call_kw  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\openerp\addons\web\controllers\main.py", line 895, in _call_kw  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\api.py", line 250, in wrapper  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\openerp\addons\point_of_sale\point_of_sale.py", line 798, in create_from_ui  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\api.py", line 250, in wrapper  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\openerp\addons\point_of_sale\point_of_sale.py", line 741, in _process_order  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\api.py", line 250, in wrapper  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\openerp\addons\point_of_sale\point_of_sale.py", line 711, in _get_valid_session  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\api.py", line 250, in wrapper  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\openerp\addons\point_of_sale\point_of_sale.py", line 545, in create  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\api.py", line 250, in wrapper  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\api.py", line 354, in old_api  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\models.py", line 4157, in create  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\api.py", line 248, in wrapper  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\api.py", line 490, in new_api  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\models.py", line 4354, in _create  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\api.py", line 248, in wrapper  File "C:\Program Files (x86)\Odoo 9.0-20161004\server\.\openerp\models.py", line 1271, in _validate_fieldsValidationError: (u'You cannot create two active sessions related to the same point of sale!', None)