Ubuntu system freeze on Rstudio startup


I have troubles starting Rstudio on Ubuntu. It worked up until last week but now it completely freezes the system.
The problem is similar to this thread: https://support.rstudio.com/hc/en-us/community/posts/207006938-RStudio-freezes-when-saving-or-loading

However I don't even get any output if I run:
file rstudio
Instead the system immediately freezes and I have to reboot. Searching for the lock file doesn't produce any results. Removing profile or environment files or reinstalling doesn't help either.
R by itself runs fine in the Terminal.

R-version: R version 3.4.4 (2018-03-15)
R-studio version: RStudio 1.1.453 - Ubuntu 16.04+/Debian 9+ (64-bit)
Ubuntu version: Description: Ubuntu 16.04.4 LTS

Any help would be very much appreciated!
Thank you

Sorry about the issue,

Below is the support trouble-shooting guide for this type of issue.

Failing those steps, the following info could be helpful;