Error: Please select a payment method for your order

I added the Purchase Order module to my shopping cart and just changed it to say CC Paid at Show. This module has worked before and I tried switching it back to Purchase Order, but it's not matter. I still get this error:
Please select a payment method for your order.

When I disable the authorize.net module it lets me go through CC Paid at Show with no problem. But as soon as I enable both, I get the error when I choose CC Paid at Show.

I'm not sure why I'm getting this error.

My site is http://wholesale.xoticeyes.com

You can login to try it out using my test login.

It's mapruter######################
password

I am using ZenCart 1.4.9. I have put off updating because of all the changes to files I've made (changes I made before I understood making changes to a TEMPLATE_FILE, so it's going to be a process that I just need the time for).

I appreciate any help in advance.

mapruter is a gmail . com account.

I just spoke to a client on the phone, and apparently when there is an option, using the CC method also brings up the same error. But when I remove the CC Paid at show he has no problem processing his order.

I fixed it. But in a way that doesn't really address the issue.

I have two sites with the same products, a retail and a wholesale. The wholesale one is the one having the issue.

So I cloned the retail site and uploaded parts of the database I needed from the wholesale's original db (admin info, customer info, product info, coupons, etc). And now everything is working.

This method was actually a hell of a lot faster of a solve. I spent over 10 hours trying to fix the issue and only 2.5 hours to clone the retail site and upload parts of the wholesale db.

In this case, I would suggest you make frequent backups of your site. Esp before you install any new modules. And when you find a problem you can't solve that wasn't an issue before, start working backward in your backups to a place when the issue wasn't there. And maybe that'll help identify the module that could have caused the break.

Hopefully this helps someone.