Example, run a workflow, a message box pops up. How to clear the pop-up message box when you click on an element in Internet Explorer
What is the purpose of using the Message Box? Unless you are using it to stop your process for testing then do you really need it? Could you substitute it with the Log Message Activity.
If you definitely need it within your process then you could automate clicking OK on the Message Box just as you would with any other Click Button step.
you can’t record that click “ok” on message box as it in run time.