I double checked by searching our entire source tree for that message >> nothing.
Note that someone could have modified your TestStand installation without creating an installer for their modification, in which case it wouldn't show up in the Add/Remove programs control panel.
Most likely a message like this is being displayed by a custom UI or a custom process model. If it still happens when you use the NI supplied sequence editor, then make sure you are using an unmodified NI supplied process model. Also try using no process model at all.
Another possibility is than the sequence itself is calling code that displays the message.
