Magento Payment goes through after Place Order, but no Success Page Redirect

[Jeffunlimited]

After upgrading to Magento 1.9, payments are processed at the checkout, but there is no success message. After going through the checkout proccess and clicking place order, the payment goes through, but the item stays in the cart and no success redirect occurs. The order shows up normally in the backend as well as processing. There doesn't seem to be a clear solution from Magento. Can anyone point me in the right direction? Even after going over error logs I have no idea what could be causing this. Thank you.

[RichardH]

Which Magento payment module for Authorize.Net are you using and how do you have it configured?

[Jeffunlimited]

I'm using Authorize.net. I don't have direct post setup.

Enabled	Yes	[WEBSITE]
Title	Credit Card (Authorize.net)
API Login ID	******
Payment Action	Authorize OnlyAuthorize and Capture	[WEBSITE]
Transaction Key	******
New Order Status	Processing	[WEBSITE]
Test Mode	No	[WEBSITE]
Gateway URL	https://secure.authorize.net/gateway/transact.dll
Accepted Currency	US	[WEBSITE]
Debug	No	[WEBSITE]
Email Customer	No

Also I have "No" for Credit Card Verification

[RichardH]

If the Authorize.Net module for Magento you are using is based on our Direct Post Method (DPM) they you must have it properly configured in order for the gateway to POST transaction responses back to Magento.

Richard

[Jeffunlimited · Accepted solution]

Thank you for the help. I was able to solve the problem. I needed to add the mb_string module in the Exhaustive Options (Step 5) of the EasyApache Wizard. I know many people have encountered this issue. If this [Fatal error: Call to undefined function mb_convert_encoding()] comes up it is likely a server issue and upgrades may be required through WHM.

[virus77]

Sorry, can't see the solution. 

Please give me new link.