I have error when i reply attachment from messaging, i'm try with csv, pdaf and jpeg and i found same like error, please see below for error

OpenERP Server Error

Client Traceback (most recent call last):


File "/opt/openerp/server/openerp/addons/web/http.py", line 203, in dispatch
response["result"] = method(self, **self.params)


 File "/opt/openerp/server/openerp/addons/web/controllers/main.py", line 1117, in call_kw
return self._call_kw(req, model, method, args, kwargs)
File "/opt/openerp/server/openerp/addons/web/controllers/main.py", line 1109, in _call_kw
return getattr(req.session.model(model), method)(*args, **kwargs)


 File "/opt/openerp/server/openerp/addons/web/session.py", line 43, in proxy
result = self.proxy.execute_kw(self.session._db, self.session._uid, self.session._password, self.model, method, args, kw)



File "/opt/openerp/server/openerp/addons/web/session.py", line 31, in proxy_method
result = self.session.send(self.service_name, method, *args)


File "/opt/openerp/server/openerp/addons/web/session.py", line 104, in send
    raise xmlrpclib.Fault(openerp.tools.ustr(e), formatted_info)


Server Traceback (most recent call last):
  File "/opt/openerp/server/openerp/addons/web/session.py", line 90, in send
    return openerp.netsvc.dispatch_rpc(service_name, method, args)
  File "/opt/openerp/server/openerp/netsvc.py", line 293, in dispatch_rpc
    result = ExportService.getService(service_name).dispatch(method, params)
  File "/opt/openerp/server/openerp/service/web_services.py", line 618, in dispatch
    res = fn(db, uid, *params)
  File "/opt/openerp/server/openerp/osv/osv.py", line 188, in execute_kw
    return self.execute(db, uid, obj, method, *args, **kw or {})



 File "/opt/openerp/server/openerp/osv/osv.py", line 131, in wrapper
    return f(self, dbname, *args, **kwargs)
  File "/opt/openerp/server/openerp/osv/osv.py", line 197, in execute
    res = self.execute_cr(cr, uid, obj, method, *args, **kw)
  File "/opt/openerp/server/openerp/osv/osv.py", line 185, in execute_cr
    return getattr(object, method)(cr, uid, *args, **kw)
  File "/opt/openerp/server/openerp/addons/mail/mail_thread.py", line 962, in message_post
    ir_attachment.write(cr, SUPERUSER_ID, filtered_attachment_ids, {'res_model': model, 'res_id': thread_id}, context=context)
  File "/opt/openerp/server/openerp/addons/document/document.py", line 129, in write
    return super(document_file, self).write(cr, uid, ids, vals, context)
  File "/opt/openerp/server/openerp/addons/base/ir/ir_attachment.py", line 268, in write
    self.check(cr, uid, ids, 'write', context=context, values=vals)
  File "/opt/openerp/server/openerp/addons/document/document.py", line 76, in check
    return super(document_file, self).check(cr, uid, ids, mode='read', context=context, values=values)
  File "/opt/openerp/server/openerp/addons/base/ir/ir_attachment.py", line 208, in check
    mids = self.pool.get(model).exists(cr, uid, mids)
AttributeError: 'NoneType' object has no attribute 'exists'`