For some linux users (arch afaik), tuxguitar playback might not work because of newer Java. 
You'll gave to use an older version so it works again.
There's a bunch of ways on how to do it, but here's the simplest:
1. get jre11-openjdk package (java v 11)
2. using this command, open up tuxguitar: 
            JAVA_HOME=/usr/lib/jvm/java-11-openjdk tuxguitar

You can make a shell scripts that runs this command and/or edit start menu command