Save image : Object reference not set to an instance of an object, while try to capture sliding image

I’m new to Uipath, I try to capture image and save it using Take Screenshot and Save image activity, it works fine when the image is still but gets above mentioned error, when tries to capture sliding image.
Used ‘*’ & .png image file type, it saves the image but the image file is blank.
Want to save in .jpg format. Any help, much appreciated.Selectors-Download Images from JuzzGo.xaml (5.9 KB)