Yes , i have problem in 3.1 too, it seems that new released not tested at all before release / some main function stopped working like Add to card Button

Wow... that's a lot of exclamation points. I'm only trying to help and I'm simply asking questions to better understand the issue.

Sorry Will, it was absolutely not my intention to appear rude or with a strong tone, I’m only happy to make me useful to help you in built a better product and I hope to be appreciated for this.
My english is no good and to write I often help me with google translate, but equally some times I seem unable to make myself understood in the right way.
I just wanted to be as clear as possible and to give my help where I can, but as often happens I'm misunderstood. Sorry again, in the future I will be more attentive to the exclamation points!! ;-))

Well, I found where is the problem. The bug comes out of "Enahncements to allow promotions work at variant level" commit ([url=https://github.com/HotcakesCommerce/core/commit/91ef94534e1da0e22f607e934a059f10cda86220#diff-f6cfa8bb4203d547d5000d4578deeb84http://]link here[/url]) about Libraries/Hotcakes.Commerce.Dnn/Web/HotcakesModuleBase.cs file.
At line 211 the previous code on HCC 3.0.1 was
This pull change adds the culture name to the portal url, I don't know the reason of this change but the problem is that the addition of the culture name parameter on the base url cause the mismatch of the registered routes for APIs calls.
For example the product details view use some javascript function that call the Product/Validate API, but if in the base url is present the culture name it is no more able to find the registered route.
I'm no a programmer and I'm no able to fork and push this on github, but this is the origin of this and [url=https://mmmcommerce.com/Forums/g/posts/t/144/find/unread/HC-3-0-1-upgraded-to-HC-3-1-0]this other[/url] 3.1.0 multilanguage bugs.
For those who need this correction right away, [url=http://95.110.156.198/ForumImages/Hotcakes.Commerce.Dnn.dll]here[/url] you can find the link to the recompiled Hotcakes.Commerce.Dnn.dll waiting for a new official version to be released.

Hey Scippy:

Thanks for your updates on this. I appreciate your explanation of both points. :)

I want to make sure I understand correctly... Did you test this recompiled code and find it to work? Am I to understand that you changed it to be the line of code found in version 03.00.01?