Hi there,
updating flatpak install these packages:
flatpak update
Looking for updates…
Required runtime for org.gtk.Gtk3theme.Mint-Y/x86_64/3.22 (runtime/org.freedesktop.Platform/x86_64/18.08) found in remote flathub
Do you want to install it? [Y/n]: Y
ID Arch Branch Remote Download
1. org.freedesktop.Platform x86_64 18.08 flathub < 295,2 MB
2. org.freedesktop.Platform.Locale x86_64 18.08 flathub < 316,0 MB (partial)
3. org.freedesktop.Platform.VAAPI.Intel x86_64 18.08 flathub < 1,8 MB
4. org.freedesktop.Platform.html5-codecs x86_64 18.08 flathub < 3,3 MB
Proceed with these changes to the Default system installation? [Y/n]:
then flatpak uninstall --unused remove these as unused again
flatpak uninstall --unused
ID Arch Branch
1. [-] org.freedesktop.Platform.VAAPI.Intel x86_64 18.08
2. [-] org.freedesktop.Platform.html5-codecs x86_64 18.08
3. [-] org.freedesktop.Platform x86_64 18.08
4. [-] org.freedesktop.Platform.Locale x86_64 18.08
Uninstall complete.
Thanks in advance