How to run GIMP on Ubuntu 16.04 (install from flatpak)?

Type in terminal

flatpak run org.gimp.GIMP

Then it will open GIMP

Open the terminal and run the command:

sudo apt install flatpak

This should install the necessary items for the unwrapping of Gimp. Then type in:

flatpak install https://flathub.org/repo/appstream/org.gimp.GIMP.flatpakref

This should allow you to download and install Gimp into your computer.

Then run: flatpak run org.gimp.GIMP

It should now be running.

Why are you trying to install GIMP from a Flatpack package instead of installing the native GIMP snap package? To install the latest version of GIMP in all currently supported versions of Ubuntu open the terminal and type:

sudo snap install gimp  

If you need to have full access to external media (such as USB flash drive, SD/MicroSD card, additional mounted hard drive and so on), run the following command:

sudo snap connect gimp:removable-media

You can also install the latest version of GIMP (v2.10) from the Ubuntu Software app by selecting the GIMP snap package which is called GIMP in Ubuntu Software or in Ubuntu 18.10 and later you can install GIMP (v2.10) using apt with sudo apt install gimp

snapd autoupdates installed snap packages by default.