Fatal error: Uncaught InvalidArgumentException: Constant name is expected. in /home/koala/public_html/vendor/magento/framework/Data/Argument/Interpreter/Constant.php:23 Stack trace: #0 /home/koala/public_html/vendor/magento/framework/Data/Argument/Interpreter/Composite.php(61): Magento\Framework\Data\Argument\Interpreter\Constant->evaluate(Array) #1 /home/koala/public_html/vendor/magento/framework/Data/Argument/Interpreter/ArrayType.php(44): Magento\Framework\Data\Argument\Interpreter\Composite->evaluate(Array) #2 /home/koala/public_html/vendor/magento/framework/Data/Argument/Interpreter/Composite.php(61): Magento\Framework\Data\Argument\Interpreter\ArrayType->evaluate(Array) #3 /home/koala/public_html/vendor/magento/framework/ObjectManager/Config/Mapper/Dom.php(102): Magento\Framework\Data\Argument\Interpreter\Composite->evaluate(Array) #4 /home/koala/public_html/vendor/magento/framework/Config/Reader/Filesystem.php(176): Magento\Framework\ObjectManager\Config\Mapper\Dom->convert(Object(DOMDocument)) #5 /home/koala/publi in /home/koala/public_html/vendor/magento/framework/Data/Argument/Interpreter/Constant.php on line 23