Odd behavior in RStudio

RStudio IDE
1

Everything was working fine today until after I returned from lunch... Since then my RStudio has been acting up. I have closed and reopened RStudio a couple of times and even restarted my computer. After a few minutes of not being able to do anything in RStudio other than edit source code, the following errors begin to populate:

Warning: unable to access index for repository https://cran.rstudio.com/src/contrib:
  cannot open URL 'https://cran.rstudio.com/src/contrib/PACKAGES'
Warning: unable to access index for repository http://www.stats.ox.ac.uk/pub/RWin/src/contrib:
  Line starting '<!doctype html> ...' is malformed!

Also when trying to install a package, I get:

install.packages("dplyr") 
Warning in install.packages :
  unable to access index for repository https://cran.rstudio.com/src/contrib:
  cannot open URL 'https://cran.rstudio.com/src/contrib/PACKAGES'
Error in install.packages : unknown input format

I have not been able to complete any work this afternoon, any suggestions?

2

I think I had that once. How fresh is your R/RStudio? I'd just reinstall them, that's probably faster than trying to debug it. It worked for me.

Good luck!

3
Some system Information could be useful as well 

#### System Information:
- RStudio Edition: (Desktop or Server)
- RStudio Version: 
- OS Version: 
- R Version: 

#### Also:
<!-- Depending on your issue, the following may be useful /-->
<!-- If a section isn't relevant or you can't collect it just delete that section below /-->
- RStudio diagnostics report: <!--see rstd.io/support-diagnostics-report /-->
- Your `sessionInfo()`:
- RStudio crash report: <!-- rstd.io/support-crash-report /-->
- RStudio application log files: <!-- rstd.io/support-ide-log-files /-->

There is some discussion here: