Recently ran into a problem when I was configuring a LabVIEW module that passed in/out clusters/types. I had a mistake in my code that the teststand data type was not configured to allow it to pass to LabVIEW clusters, but the problem was not as obvious as I thought it should be.
Here's what I had:

And when I click on the red checkmark "check expression" for "Cluster", it shows up as "No Errors". Everything looks great, right? Well, it isn't.
It's not until I expand "Cluster" to show the elements that I see that there are connectivity problems.

It would be nice if "Locals.mylocal" expression would turn RED and show a "check expression error" if any of it's children also had a connection problem (specifically in this case that the type in TestStand was not configured to allow passing to LabVIEW clusters). This way it would be a lot easier to see.
Even worse, this problem is NOT found by sequence analyzer -- it's left to be found at runtime.
I know this is all because I had a bug/mistake in my code, but it would be a lot easier to track down and fix if these changes were made.