If the $op equal to create then $entity can be string

I am getting a notice error (Trying to get property of non-object) after the menu cache clear with the commerce_coupon module installed.

This line is the problem in the function commerce_entity_access().

return user_access('create ' . $entity_type . ' entities', $account) || user_access('create ' . $entity_type . ' entities of bundle ' . $entity->{$entity_info['entity keys']['bundle']}, $account);