Yes, I have disabled all the plugins except MarketPress Lite, but the problem persists. We use the Twenty Eleven theme.
Specifically, the problem comes during the checkout process. Everything works well until I reach the 'Payment Information' screen. So I am able to:
-Add items to the cart
-Click the 'checkout now' button
-Input shipping information
-Click the 'continue checkout' button.
After inputting shipping info and clicking the 'continue checkout' button, I am at the 'Payment Information' screen. When all three options are active, the Payment Information screen prompts users to "Choose a payment method." Users can select Manual Payments, Paypal, or Credit Card (Simplify). Here is the problem:
-If I select Manual Payment and then click the 'continue checkout' button, nothing happens.
-If I select Paypal and then click the 'continue checkout' button, nothing happens.
-If I select Credit Card, fields appear to enter my credit card info (I'm still on the Payment Info page at this point). Once I enter my cc info, I can then click the 'continue checkout' button and am taken to the 'Confirm Your Purchase' page. I can click the 'confirm payment' button and complete my transaction.
If I disable the Simplify Commerce option in the MarketPress Lite settings, then the Paypal and Manual payment options work fine, and I can complete transactions using either payment method.
Not sure if this info is helpful: Our server is running PHP version 5.2.13 and MySQL version 5.0.96.
Please let me know if I can do anything else to help pinpoint the problem. We have been using MarketPress Lite for several years with much success. We were thrilled to see the Simplify Commerce option and hope we can get it working.
Thank you so much for your help.