Notice: Undefined index: extension in /var/www/imgopt/apps/convert.php on line 49

Fatal error: Uncaught TypeError: Argument 1 passed to Images\Utils\ConvertParam::convertExtension() must be of the type string, null given, called in /var/www/imgopt/apps/convert.php on line 64 and defined in /var/www/imgopt/apps/class/utils/ConvertParam.php:126 Stack trace: #0 /var/www/imgopt/apps/convert.php(64): Images\Utils\ConvertParam->convertExtension(NULL) #1 /var/www/imgopt/public/common.php(7): require_once('/var/www/imgopt...') #2 /var/www/imgopt/public/nightsfun/convert.php(5): require_once('/var/www/imgopt...') #3 {main} thrown in /var/www/imgopt/apps/class/utils/ConvertParam.php on line 126