I appreciate the response matt, and I know it's almost impossible to respond other than try reinstalling. The problem is I am not getting an error. The shiny app launches but doesn't run. I did notice the dateRangeInput dates would not pre-populate any more with my default values. Other than that, I don't know how to diagnose, but I do know it has something to do with the RStudio update as the exact same code runs fine on RStudio 1.2.5001