I resorted to flatpak after attempting to install a tar.gz file that did not have a install.sh file.

I can install a flatpak app but I cannot launch it.

When I put 'flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo' nothing seems to happen.

This is one output from attempting to launch Pioneer:

System Name: Linux
Host Name: NAME OF MY COMPUTER
Release(Kernel) Version: 4.15.0-45-generic
Kernel Build Timestamp: #48-Ubuntu SMP Tue Jan 29 16:28:13 UTC 2019
Machine Arch: x86_64
Domain Name: (none)

libGL error: No matching fbConfigs or visuals found
libGL error: failed to load driver: swrast
X Error of failed request: BadValue (integer parameter out of range for operation)
Major opcode of failed request: 154 (GLX)
Minor opcode of failed request: 3 (X_GLXCreateContext)
Value in failed request: 0x0
Serial number of failed request: 108
Current serial number in output stream: 109

And I resorted to trying out SuperTux 2 to see if it was the app:

libGL error: No matching fbConfigs or visuals found
libGL error: failed to load driver: swrast
X Error of failed request: BadValue (integer parameter out of range for operation)
Major opcode of failed request: 154 (GLX)
Minor opcode of failed request: 3 (X_GLXCreateContext)
Value in failed request: 0x0
Serial number of failed request: 108
Current serial number in output stream: 109

Did I configure my computer poorly?