I downloaded Pencil from https://pencil.evolus.vn and installed the .deb file successfully but whenever I try to open the application nothing happens. it appears in the dock for a few moments but it won't open. is there something missing?!
I'm on ubuntu 18.4 (kernel version : 4.17)
Try running the program in question from the terminal. This often gives a better view of what might be going wrong when it is not starting. Especially if you installed a program via dpkg, which has no dependency tracking built in like apt, you can easily forget some package the application needs to work.
Watch out for missing library packages in particular.
In this case the package depends on the libgconf-2-4 package, which you can install using the following command:
sudo apt install libgconf-2-4
