We backup the magento 1.9x then got a Fatal error,Who can help us solve this problem.
Fatal error: Class name must be a valid object or a string in /home/tool/public_html/cart/includes/src/__default.php on line 30729
You need to turn off compilation before upgrading your installation. Here's an example what to do: https://kb.magenting.com/content/24/81/en/disable-magento-compiler.html
@lapiarytool Did you ever find a solution to this? I am running in to the same issue