I successfully create customer invoice in my module. but when i send E-mail to the customer.

this invoice is under accounting module.

i got this error.

Odoo

OpenERP Server Error

Traceback (most recent call last): File "/home/jayson/odoo/openerp/http.py", line 476, in _handle_exception return super(JsonRequest, self)._handle_exception(exception) File "/home/jayson/odoo/openerp/http.py", line 495, in dispatch result = self._call_function(**self.params) File "/home/jayson/odoo/openerp/http.py", line 311, in _call_function return checked_call(self.db, *args, **kwargs) File "/home/jayson/odoo/openerp/service/model.py", line 113, in wrapper return f(dbname, *args, **kwargs) File "/home/jayson/odoo/openerp/http.py", line 308, in checked_call return self.endpoint(*a, **kw) File "/home/jayson/odoo/openerp/http.py", line 685, in __call__ return self.method(*args, **kw) File "/home/jayson/odoo/openerp/http.py", line 360, in response_wrap response = f(*args, **kw) File "/home/jayson/odoo/addons/web/controllers/main.py", line 983, in call_kw return self._call_kw(model, method, args, kwargs) File "/home/jayson/odoo/addons/web/controllers/main.py", line 975, in _call_kw return getattr(request.registry.get(model), method)(request.cr, request.uid, *args, **kwargs) File "/home/jayson/odoo/openerp/api.py", line 204, in wrapper return old_api(self, *args, **kwargs) File "/home/jayson/odoo/openerp/api.py", line 325, in old_api result = method(recs, *args, **kwargs) File "/home/jayson/odoo/openerp/models.py", line 5610, in onchange record._onchange_eval(name, field_onchange[name], result) File "/home/jayson/odoo/openerp/models.py", line 5549, in _onchange_eval method_res = getattr(self._model, method)(*args) File "/home/jayson/odoo/openerp/api.py", line 204, in wrapper return old_api(self, *args, **kwargs) File "/home/jayson/odoo/addons/email_template/wizard/mail_compose_message.py", line 101, in onchange_template_id values = self.generate_email_for_composer_batch(cr, uid, template_id, [res_id], context=context)[res_id] File "/home/jayson/odoo/openerp/api.py", line 204, in wrapper return old_api(self, *args, **kwargs) File "/home/jayson/odoo/addons/email_template/wizard/mail_compose_message.py", line 163, in generate_email_for_composer_batch template_values = self.pool.get('email.template').generate_email_batch(cr, uid, template_id, res_ids, fields=fields, context=ctx) File "/home/jayson/odoo/openerp/api.py", line 204, in wrapper return old_api(self, *args, **kwargs) File "/home/jayson/odoo/addons/email_template/email_template.py", line 488, in generate_email_batch result, format = self.pool['report'].get_pdf(cr, uid, [res_id], report_service, context=ctx), 'pdf' File "/home/jayson/odoo/openerp/api.py", line 204, in wrapper return old_api(self, *args, **kwargs) File "/home/jayson/odoo/addons/report/models/report.py", line 176, in get_pdf save_in_attachment = self._check_attachment_use(cr, uid, ids, report) File "/home/jayson/odoo/openerp/api.py", line 204, in wrapper return old_api(self, *args, **kwargs) File "/home/jayson/odoo/addons/report/models/report.py", line 326, in _check_attachment_use pdf = base64.decodestring(pdf) File "/usr/lib/python2.7/base64.py", line 321, in decodestring return binascii.a2b_base64(s) TypeError: must be string or buffer, not None

How to Fix This is there any one can help me im stack in here :(