Hello @Currurant,
I'm sorry to hear you've been having problems. I was able to move your .rstudio metadata out of the way /home/rstudio-user/.rstudio moved into /home/rstudio-user/.rstudio.old and your .Rproj.user data as well from /cloud/project/.Rproj.user to /cloud/project/.Rproj.user.old and now your project launches.
In the future you could try the Relaunch Project button, which would accomplish this as well.
-Josh