With WHMCS 6 there is automatically a link to the statement added to the template using HOOKS, but unfortunately not in WHMCS 5.
What can I do about this?
The most simple solution is to simply add the link to your account statement file manually. Simply follow the steps below and you will be ready to go in no time.
1. Move WHMCS -> templates -> SIX -> account_statement.tpl To WHMCS -> templates -> Your Template Folder-> account_statement.tpl
2. Add the link to your account_statement.php file manually to your menu or template files where you need it.
3. Test... You are now done and dusted!!!