Fresh Shiny Server installation problems: Starting listener on http://[::]:3838

shiny-server

#1

I have developed a shiny app using RStudio. I now want to make this available to my work colleagues.
So I have installed Shiny Server open source edition.
I am running Ubuntu 18.04.1 LTS
I have followed the instructions here:

Immediately after running sudo gdebi shiny-server.deb, the instructions says

Shiny Server should now be installed and running on port 3838 . You should be able to see a default welcome screen at http://your_server_ip:3838/ .

However, when I point my browser there, the welcome screen appears but the test apps on the right side do not run, and instead show: " An error has occurred .The application failed to start. The application exited during initialization."

/var/log/shiny-server.log has these entries

[2018-10-02T09:24:47.596] [INFO] shiny-server - Starting listener on http://[::]:3838
[2018-10-02T09:26:17.439] [INFO] shiny-server - Error getting worker: Error: The application exited during initialization.

I was expecting to see "Starting listener on http://localhost:3838" or something similar, so this doesn't seem right. I was unable to find a solution in the admin guide.

Any suggestions ?

EDIT: Is there any further information I can provide in order to get some help with this ?