title: Issue: Working Directory in R Studio "stuck" on directory containing open R Markdown file
body: <p>I am using the most recent version of R (3.3.2), running in the most recent version of RStudio (1.0.136) on MacOS Sierra (10.12.3). I am running into an issue in which my working directory corresponds, and is stuck on, the directory that contains the .RMD file I currently have open in RStudio. Upon opening the file, the working directory is correctly set to the directory holding the .Rproj file. When I go to load in a file with a path relative to that directory, however, I get an error that there is no such file in the current working directory, and the error returns the location of the .RMD file as that working directory.</p>
  
  <p>The working directory, however (using <code>getwd()</code>) still reads where the working directory is <em>supposed</em> to be, and no matter where I try to set it, I still get the same error message when I try to read in a file. Notably, I do NOT get an error message that the working directory cannot be changed--R tells me that the working directory has been changed, and that directory is allegedly the current working directory...but it's not.</p>
  
  <p>I have tried fully (as far as I am aware) uninstalling R and R studio and reinstalling them, to no avail. Does anyone have a solution? This is frustrating the heck out of me right now, since I have to revise all the relative paths in the notebooks that I have defined to do my work in the interim.</p>
  
  <p>Extra information in case it's relevant: I restored from a Time Machine backup that I suspect may have been corrupted somehow; some contents of my Applications folder were missing that I had to move over manually. Could this be causing the issue? Are there other system files that R depends on when interacting with the filesystem that I might look to? I'm trying to avoid doing a clean OS install or a piecemeal rebuilding of my files, since I don't know if that's actually the issue.</p>
  
  <p>Thanks in advance!</p>