Hi gravy,
It is very odd that the VI was working earlier, and now all of a sudden does not. There is probably something that has changed about the application that has created this error.
The first place I would have gone would have been to check and make sure that the VI's code had not been altered in any way, but if that were the case it would have been fixed when you downloaded the driver again. There are a few other possible places that could be the cause of this problem, however. Some things to check are to ensure that all of the inputs are the same and wired into the same terminals on the Getting Started VI, and that all of the settings on the instrument are the same.
If you are sure that the setup is exactly the same, then I recommend running it in highlight execution mode (the lightbulb on the toolbar at the top of the block diagram) to see exactly where this error is occurring. From there we can dig in deeper and see what is going on.
John M
Applications Engineer
