Attempting to open a Point of Sale session on a specific POS gives me the following error:

Client Traceback (most recent call last): File "/opt/openerp/v7/web/addons/web/http.py", line 204, in dispatch response["result"] = method(self, *self.params) File "/opt/openerp/v7/web/addons/web/controllers/main.py", line 1128, in call_kw return self._call_kw(req, model, method, args, kwargs) File "/opt/openerp/v7/web/addons/web/controllers/main.py", line 1114, in _call_kw records = req.session.model(model).read(args, **kwargs) File "/opt/openerp/v7/web/addons/web/session.py", line 42, in proxy result = self.proxy.execute_kw(self.session._db, self.session._uid, self.session._password, self.model, method, args, kw) File "/opt/openerp/v7/web/addons/web/session.py", line 30, in proxy_method result = self.session.send(self.service_name, method, *args) File "/opt/openerp/v7/web/addons/web/session.py", line 103, in send raise xmlrpclib.Fault(openerp.tools.ustr(e), formatted_info)

Server Traceback (most recent call last): File "/opt/openerp/v7/web/addons/web/session.py", line 89, in send return openerp.netsvc.dispatch_rpc(service_name, method, args) File "/opt/openerp/v7/server/openerp/netsvc.py", line 292, in dispatch_rpc result = ExportService.getService(service_name).dispatch(method, params) File "/opt/openerp/v7/server/openerp/service/web_services.py", line 626, in dispatch res = fn(db, uid, params) File "/opt/openerp/v7/server/openerp/osv/osv.py", line 188, in execute_kw return self.execute(db, uid, obj, method, *args, *kw or {}) File "/opt/openerp/v7/server/openerp/osv/osv.py", line 131, in wrapper return f(self, dbname, args, *kwargs) File "/opt/openerp/v7/server/openerp/osv/osv.py", line 197, in execute res = self.execute_cr(cr, uid, obj, method, args, *kw) File "/opt/openerp/v7/server/openerp/osv/osv.py", line 185, in execute_cr return getattr(object, method)(cr, uid, args, *kw) File "/opt/openerp/v7/server/openerp/osv/orm.py", line 3604, in read result = self._read_flat(cr, user, select, fields, context, load) File "/opt/openerp/v7/server/openerp/osv/orm.py", line 3724, in _read_flat res2 = self._columns[f].get(cr, self, ids, f, user, context=context, values=res) File "/opt/openerp/v7/server/openerp/osv/fields.py", line 1133, in get result = self._fnct(obj, cr, uid, ids, name, self._arg, context) File "/opt/openerp/v7/server/openerp/osv/fields.py", line 1199, in _fnct_read value = value[field] or False File "/opt/openerp/v7/server/openerp/osv/orm.py", line 399, in __getitem__ field_values = self._table.read(self._cr, self._uid, ids, field_names, context=self._context, load="_classic_write") File "/opt/openerp/v7/server/openerp/osv/orm.py", line 3604, in read result = self._read_flat(cr, user, select, fields, context, load) File "/opt/openerp/v7/server/openerp/osv/orm.py", line 3724, in _read_flat res2 = self._columns[f].get(cr, self, ids, f, user, context=context, values=res) File "/opt/openerp/v7/server/openerp/osv/fields.py", line 1133, in get result = self._fnct(obj, cr, uid, ids, name, self._arg, context) File "/opt/openerp/v7/addons/account/account_cash_statement.py", line 126, in _compute_difference result[obj.id] = obj.balance_end_real - obj.balance_end File "/opt/openerp/v7/server/openerp/osv/orm.py", line 486, in __getattr__ raise AttributeError(e) AttributeError: 'Field balance_end_real not found in browse_record(account.bank.statement, 467)'

In the "All Sessions" menu, it is shown as at "Opening Control" and assigned to me. I don't know exactly what happened to the system as I was not present when it went down and no one can give me a straight answer as to what was done in the time I was gone. I've created a new POS and it runs fine, so there's nothing in the code, it has to be a database or settings error.