After updating to RStudio version 1.2.5033 I was not able to load or save R files to any directory on my office thin client, other than the desktop. There have been a number of similar topics listed but no solution other than to suggest users contact their IT admin.
However when I go back to version 1.1.463 no problem which would suggest to me a RStudio is the problem not a system IT issue.
Now because RStudio/R has not yet been approved for my office baseline I have to run RStudio from a folder in My Documents which has worked just fine until I uploaded and tried to run version 1.2.5033
Reference : Cannot save R scripts