RStudio initialization error, unexpected exception, fatal error

I am having an issue starting RStudio (desktop) that I did not have before.

When I fire-up RStudio, within seconds, the grey screen freezes with the following error message:

RStudio Initialization Error
Unable to establish connection with R session

Once I click 'OK', I get the following two error messages:

Unexpected exception: The complexity of the regular expression exceeded predefined bounds...


R encountered a fatal error. The session was terminated.

Any help in resolving these errors is much appreciated.

The "unexpected exception" error reads as though something's going wrong with RStudio trying to run something it's loading automatically as it is starting up. So, the related question is: how can I start RStudio fresh without opening any of the previous files/code/data?

I have tried uninstalling and reinstalling both R and RStudio, and R is installed fine (I can open and work on the R console).

I am working with:

  • Mac OSX 10.10.5
  • R 3.3.3
  • RStudio 1.1.423

Thank you!

Thanks for the bug report! Indeed, RStudio is crashing while attempting to open a file you had opened from a previous session. You should be able to work around this by resetting your RStudio state.

If this doesn't help, you might also try testing out one of the daily builds of RStudio, to see if the issue is resolved there (it hopefully should be!)

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