ERROR:tryton.common.common: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 154, in dispatch
    result = rpc.result(meth(*args, **kwargs))
  File "/trytond/ir/sequence.py", line 195, in delete
    return super(Sequence, cls).delete(sequences)
  File "/trytond/model/modelsql.py", line 1074, in delete
    field_name: False,
  File "/trytond/modules/account_invoice/account.py", line 213, in write
    super(Period, cls).write(periods, vals)
  File "/trytond/modules/account/period.py", line 223, in write
    super(Period, cls).write(periods, vals)
  File "/trytond/model/modelsql.py", line 932, in write
    cls._validate(records)
  File "/trytond/model/modelsql.py", line 2231, in _validate
    super(ModelSQL, cls)._validate(records)
  File "/trytond/model/modelstorage.py", line 884, in _validate
    if not call(field[0]):
  File "/trytond/model/modelstorage.py", line 882, in call
    return all(method(r) for r in records)
  File "/trytond/model/modelstorage.py", line 882, in <genexpr>
    return all(method(r) for r in records)
  File "/trytond/modules/account_invoice/account.py", line 174, in check_invoice_sequences
    (sequence_name, '=', sequence.id),
AttributeError: 'NoneType' object has no attribute 'id'

'NoneType' object has no attribute 'id'



En 2.8 cela semble fixé par issue2916.

Après ajout du test sur "sequence" (http://hg.tryton.org/modules/account_invoice/file/4d3e00bb65ca/account.py#l182), ce message apparait:

The field "Customer Credit Note Sequence" on "Period" is required. (alors que la séquence n'est pas utilisée "Fiscal years/Sequences/Customer Credit note sequence").