Thanks for reporting and I don't think the path pointing to version 1.9 is the issue. Strangely that is the same on my system and has been for awhile (I believe it is a TeX problem that actually doesn't seem to cause any issues).
Also this issue is hard to track down on different systems. Are you able to compile this TeX document outside of RStudio? Most often it is a TeX error. If not, are you able to compile a simple "Hello World" TeX document? If that works, then it is definitely the specific file.
Let me know what you are able to find out.
P.S. Please extend my best to Nick as well. :-)