How to turn on debugging in Rnw code?

I just updated my RStudio Desktop free version to the latest version 1.4.1106. I mostly program using Sweave. In the older version of RStudio I was using, the syntax editor would evaluate my R code inside my code chunks and display red X's or the usual other red notations to show that my R code had an error in a particular line of code. However, after updating to the latest version, this debugging assistance is gone and checking my code is more difficult.

For example, if I type this code:

x = c(1,2,3,)

There is no notation in my Rnw file on the sidebar or in the code itself to indicate that this line contains an empty entry and will return an error in the R console when evaluated.

I have looked through the options but cannot figure out how to turn this option back on. I am hoping it is not disabled permanently. Has anyone else had this problem and found a solution?
Thank you!