I am using Abantecart since DEc 2016 . I upgraded to version 1.2.9 on 30-01-2017 . After which payment callback success token isnt working properly

I have integrated PAYU INDIA for Payment integration . Once the payment is completed by the customer , the success call back page ends in a blank page

Following are the error logs I am getting

2017-01-31 6:44:04 - warning: AbanteCart core v.1.2.9 Illegal string offset 'name' in <b>/home/adrplupi/public_html/courses/storefront/view/default/template/responses/checkout/cart_details.tpl</b> on line <b>26</b>
2017-01-31 6:44:04 - warning: AbanteCart core v.1.2.9 Illegal string offset 'option' in <b>/home/adrplupi/public_html/courses/storefront/view/default/template/responses/checkout/cart_details.tpl</b> on line <b>29</b>
2017-01-31 6:44:04 - warning: AbanteCart core v.1.2.9 Invalid argument supplied for foreach() in <b>/home/adrplupi/public_html/courses/storefront/view/default/template/responses/checkout/cart_details.tpl</b> on line <b>29</b>
2017-01-31 6:44:04 - warning: AbanteCart core v.1.2.9 Illegal string offset 'quantity' in <b>/home/adrplupi/public_html/courses/storefront/view/default/template/responses/checkout/cart_details.tpl</b> on line <b>35</b>
2017-01-31 6:44:04 - warning: AbanteCart core v.1.2.9 Illegal string offset 'price' in <b>/home/adrplupi/public_html/courses/storefront/view/default/template/responses/checkout/cart_details.tpl</b> on line <b>36</b>
2017-01-31 6:44:04 - warning: AbanteCart core v.1.2.9 Invalid argument supplied for foreach() in <b>/home/adrplupi/public_html/courses/extensions/sales_plus/core/sales_plus.php</b> on line <b>107</b>