Problem with Checkout from Checkout_shipping

[randers]

Pro 1.0.8.16/1.0.8.17.
Problem with Checkout if the quantity ordered is greater than what is in stock.
When the Checkout button in Checkout_shipping is clicked, the Shopping_cart page opens again.
Configuration/Allow Checkout = true
Anyone know what could be wrong

[ecartz]

In general, an early troubleshooting step should be to determine if it is a core problem or a modifications problem. To do that, start with a plain vanilla test store built from a fresh download. Can you duplicate the problem? If not, start making the test store more like the store where you observed the problem. For example, you might change what modules are installed or configuration values, checking if the problem exists after each change. When you get as far as you can with that, install add-ons to make the test store more like the other store. Again, check if the problem exists after each change. It can also be helpful to keep a record of what changes you made. Because sometimes it's two changes together that are the problem.

If you have any custom hooks used in checkout, you might check those early in the process. I'm pretty sure that I've posted code to help with stock management that might have troubles if you changed from not allowing checkout to allowing.

When you find out what change causes the problem, let us know and we may be able to make further suggestions.

I tried to purchase Grapefruit from a default install (grapefruit is out of stock; with admin > Configuration > Stock > Allow Checkout set to true) and had no problem. So if this is a core or Pro problem, there is probably more to it. I'm more confident that my core install is unchanged from the default than my Pro install. But I wouldn't expect any changes to impact checkout.

If you are frustrated and would prefer to throw money rather than time at this, you could also hire one of the certified developers to do this for you.

[randers]

Installed fresh 1.0.8.16 and tested after each module and add-on was installed. The problem with checkout occurs after installing the add-on "QTpro Phoenix 7.4.5".

[ecartz]

If it's the free version, you could probably get more help at app.php/addons/free_addon/qtpro/support

If the paid version, presumably Rainer provided some other form of contact for support.