I have found that on occasion RStudio will not save (Ctrl + S) my scripts. Nothing really happens when I try to save and when I try to close down RStudio it prompts me to save my scripts. When confirm, the software will simply not shut down.
My organisation prefers me to save work to Google Drive, so it is possible that this issue is related to this. I have not yet tried to reproduce the problem on a local drive.
Rstudio Version 1.2.1326