GoDaddy user trying to setup PayPal Express

I am a GoDaddy user trying to setup PayPal Express. This is a new install of Zen Cart 1.3.8a. and I have PHP Version: PHP 4.x and MySQL Database 5.0.
I am using the PayPal Sandbox for testing. I have “FREE SHIPPING!” enabled. I have set up only one tax zone definition while testing.
My PayPal transactions are not completing. I have PayPal debug mode enabled and each try generates about 40 email responses and the first error message shows up around the 30th one. Everything seems to work up until I press the “pay now” button on the PayPal site.
I am getting the following error message: 10413 Transaction refused because of an invalid argument. See additional error messages for details. - The totals of the cart item amounts do not match order amounts.
I have set “CURL Proxy Status = false” and had the same result. I tried the workaround to the /includes/modules/payment/paypal/paypal_functions.php. This did not work either and I have reverted to the original file.

I have probably just missed something, but I can’t find it. I hope you can help.
:frusty:

sweetV:

I have set “CURL Proxy Status = false” and had the same result. I tried the workaround to the /includes/modules/payment/paypal/paypal_functions.php. This did not work either and I have reverted to the original file.Still best to leave the CURL Proxy to False, and best to implement the changes to paypal_functions.php, since you'll still want to let PayPal properly tell your store about updates to transactions. That change is required for GoDaddy stuff to work properly.

sweetV:

I am getting the following error message: 10413 Transaction refused because of an invalid argument. See additional error messages for details. - The totals of the cart item amounts do not match order amounts.
There are a number of things that could cause the 10413 errors. Namely the calculation of line-item details. One or more of the debug messages should be telling you what's wrong with the calculations ... namely the one that deals with the SetExpressCheckout data it's sending to PayPal.

It's also worth searching the forum for other 10413 errors and their resolutions ... there have been several.

You might try turning off taxes, and turning on a simple flat-rate shipping option, and see what happens too.

BTW, I find the debug-to-email option is very hard to work with. I prefer to log-to-file instead, and grab the log files via FTP.

Many thanks for your suggestions. I will try them and let you know what happens.