Magento – Magento2: Fatal error: Uncaught Error: Cannot instantiate interface

If you use redis, run:

redis-cli flushall

If you also use an environment like ansible (lxc - server), you'll need to do that command in container. Plus I did the following:

• Clear var/generation (or generated/* in newer versions)
• Clear var/cache
• Check if the module generating the error is enabled and enable it (bin/magento module:enagle Some_Module) or Enable all Magento modules: bin/magento module:enable --all
• Compile DI bin/magento setup:di:compile

please replace your consturct code in below file /home1/dukaania/public_html/testing2/app/code/Sugarcode/Test/Model/Total/Fee.php

       public function __construct(
    \Magento\Framework\Model\Context $context,
    \Magento\Framework\Registry $registry,
     \Sugarcode\Test\Model\Total\FeeFactory $feeFactory,
    \Magento\Framework\Model\ResourceModel\AbstractResource $resource= null,
    \Magento\Framework\Data\Collection\AbstractDb $resourceCollection= null,
      array $data = array()
) {
    parent::__construct($context, $registry, $resource, $resourceCollection, 
      $data);
        $this->_feeFactory = $feeFactory;

}

after replacing run command : rm -rf generated/* and clear cache and check