Error Invoice- currency-chf: unsupported opernad type(s) *: 'NoneType' and 'Decimal'
After update from 2.2 - 2.6 want make an invoice with currency CHF , after
selecting the artikel/product this error apears:
Fehler: unsupported opernad type(s) *: 'NoneType' and 'Decimal'
Traceback (most recent call last):
File "/trytond/protocols/jsonrpc.py", line 123, in _marshaled_dispatch
response['result'] = dispatch_method(method, params)
File "/trytond/protocols/jsonrpc.py", line 156, in _dispatch
res = dispatch(*args)
File "/trytond/protocols/dispatcher.py", line 159, in dispatch
result = rpc.result(meth(inst, *args, **kwargs))
File "/trytond/modules/account_invoice/invoice.py", line 1592, in
on_change_product
currency, round=False)
File "/trytond/modules/currency/currency.py", line 236, in compute
return amount * to_currency.rate / from_currency.rate
TypeError: unsupported operand type(s) for *: 'NoneType' and 'Decimal'
... what can i change?
thanks Gunther