Change orders in backend. Can't add product.

hi

When I'm trying to add a product to an existing order I get an error message: "warning it something wrong with the form". It also say: Products marked with *** isn't avalible in choosen number".

I tried some changes in the /catalog/controller/checkout/manual.php file but without success

Does anyone have some ideas?

I run OC 1.5.6.1

You cannot ADD new Products to existing FINAL Invoices, that's all. it's neither wanted, nor planned, by default.
And if you want to sell ZERO STOCK Products, then set it in the Admin Section accordingly.
Ernie
bigmax.ch/shop/

For us, we had two different cases of not being able to add product to existing order.
One is caused by the problem that the shipping address etc fields marked with red asterisk not having filled.
The other is caused by the product to be added having a status of disabled.
Technically there is no bug for this issue in opencart, but the error/status messages were not clear and confusing. It should by design tell us the cause of the problem.