In general, waiting for a "loading please wait" to go away is very brittle and is considered "bad practice". The reason for this is Test Studio watches for it using a polling mechanism. It checks every 200ms. If the loading div comes and goes within a single 200ms time slice, Test Studio will miss it all together.
Unfortunately there are no event handles to these types of overlay div's that can be hooked into so you can sure to catch when they appear and/or disappear.
Now, after saying all that, it is still possible to work with them. There are 2 basic ways they operate:
- Some systems show and hide the overlay div. The div element is always present in the browsers DOM, just not always visible and any one moment in time. This could be why a "Wait for not exists" does not work as you expected. Instead you want to use a "Wait for not visible" step.
- Add/remove the overlay div from the browsers DOM. In this scenario a "Wait for not exist" should work.