Check out goes to 404 page

-- HikaShop version -- : 3.4.0
-- Joomla version -- : 3.8.8
-- PHP version -- : 5.6
-- Browser(s) name and version -- : Chrome

Hi
I ordered someone else to write the plugin to connect Hikashop to my bank. [Because my bank doesn't have plugin for connecting to the Hikashop]
I received the "Terminal ID", "Merchant ID" and "Transaction Key" from my bank. I've entered them into the Paymetnt Method. [screenshot attached]
I go to the front-end and add a product to card, after that I go to checkout to pay the meoney[Redirect to the bank page], but says "this page couldn't find".
Is anything that I missed it?! or the problem related to the plugin?!

We are having the same problem, only using AIM/Authorize.NET....visitors are getting credit cards processed, order status changes to confirmed, but there is no history logged on the order and customers/admins are not getting emails.

No errors in the apache logs or website error logs. This just started 5/23/2018, several days after the Joomla 3.8.8 update. I have orders prior to this that are processed okay.

EDIT: had a similar problem, but this was caused by another plugin/add-on to Hiksashop...AWO Coupon v3.5 ... so enable Debug and look for mysql errors that interfere with Hikashops' normal checkout process.

Hello,

You should directly contact the developer of your Hikashop custom payment plugin.

You should also :
- Activate the Joomla debug mode ("Administration->Global configuration->System->Debug System/Language")
- Set the "error reporting" option of the Joomla configuration to "maximum"
- Test it again so that you can see if it display an error message which will help you to understand from what your issue is coming.

Best regards,
Mohamed Thelji.