Hi @Alteryx_user_aK use a Error Messeging tool from the Interface tool category to validate each of criteria. You probaly need two of them. They will Send a Error Messege which you can tailor and and stop processing. You can click Open Example to see how they work from the Tool bar menu.
Hello Joseph, I tried using error messaging tool but it is not working.
first I dragged down text box tool. then I connected it with Error message tool. in error message tool, I have added if condition like if isNull([#1]) then "True" else "false" endif. and in below window where it says the error message when the condition true, I added the message. but when I execute it with null value, I am not getting the error message.