I'm getting an error when opening the Website Admin -> Configuration View

"Traceback (most recent call last):

File "/opt/odoo/odoo9/openerp/http.py", line 643, in _handle_exception

return super(JsonRequest, self)._handle_exception(exception)

File "/opt/odoo/odoo9/openerp/http.py", line 680, in dispatch

result = self._call_function(**self.params)

File "/opt/odoo/odoo9/openerp/http.py", line 316, in _call_function

return checked_call(self.db, *args, **kwargs)

File "/opt/odoo/odoo9/openerp/service/model.py", line 118, in wrapper

return f(dbname, *args, **kwargs)

File "/opt/odoo/odoo9/openerp/http.py", line 309, in checked_call

result = self.endpoint(*a, **kw)

File "/opt/odoo/odoo9/openerp/http.py", line 959, in __call__

return self.method(*args, **kw)

File "/opt/odoo/odoo9/openerp/http.py", line 509, in response_wrap

response = f(*args, **kw)

File "/opt/odoo/addons_ent/web/controllers/main.py", line 907, in call_kw

return self._call_kw(model, method, args, kwargs)

File "/opt/odoo/addons_ent/web/controllers/main.py", line 899, in _call_kw

return getattr(request.registry.get(model), method)(request.cr, request.uid, *args, **kwargs)

File "/opt/odoo/odoo9/openerp/api.py", line 250, in wrapper

return old_api(self, *args, **kwargs)

File "/opt/odoo/odoo9/openerp/api.py", line 381, in old_api

result = method(recs, *args, **kwargs)

File "/opt/odoo/odoo9/openerp/models.py", line 6034, in onchange

record._onchange_eval(name, field_onchange[name], result)

File "/opt/odoo/odoo9/openerp/models.py", line 5938, in _onchange_eval

method_res = getattr(self._model, method)(*args, context=self._context)

File "/opt/odoo/odoo9/openerp/api.py", line 250, in wrapper

return old_api(self, *args, **kwargs)

File "/opt/odoo/addons_ent/website/models/res_config.py", line 34, in on_change_website_id

website_data = self.pool.get('website').read(cr, uid, [website_id], [], context=context)[0]

File "/opt/odoo/odoo9/openerp/api.py", line 250, in wrapper

return old_api(self, *args, **kwargs)

File "/opt/odoo/odoo9/openerp/models.py", line 3174, in read

result = BaseModel.read(records, fields, load=load)

File "/opt/odoo/odoo9/openerp/api.py", line 248, in wrapper

return new_api(self, *args, **kwargs)

File "/opt/odoo/odoo9/openerp/models.py", line 3209, in read

self._read_from_database(stored, inherited)

File "/opt/odoo/odoo9/openerp/api.py", line 248, in wrapper

return new_api(self, *args, **kwargs)

File "/opt/odoo/odoo9/openerp/models.py", line 3400, in _read_from_database

res2 = self._columns[f].get(cr, self._model, ids, f, user, context=context, values=result)

File "/opt/odoo/odoo9/openerp/osv/fields.py", line 1494, in get

result = self._fnct(obj, cr, uid, ids, name, self._arg, context)

File "/opt/odoo/addons_ent/website_sale/models/sale_order.py", line 142, in _get_pricelist_id

pricelist = self.get_current_pricelist(cr, uid, context=context)

File "/opt/odoo/odoo9/openerp/api.py", line 250, in wrapper

return old_api(self, *args, **kwargs)

File "/opt/odoo/addons_ent/website_sale/models/sale_order.py", line 225, in get_current_pricelist

available_pricelists = self.get_pricelist_available(cr, uid, context=context)

File "/opt/odoo/odoo9/openerp/api.py", line 250, in wrapper

return old_api(self, *args, **kwargs)

File "/opt/odoo/addons_ent/website_sale/models/sale_order.py", line 203, in get_pricelist_available

request.website.user_id.sudo().partner_id.property_product_pricelist.id,

AttributeError: 'NoneType' object has no attribute 'user_id'"

I've tried to uninstall and reinstall the Website module, but I still get the same error.
I'm using the Theme Blueboy from 73 Lines.