India income tax returns filing utilities are created using Java 8 SDK and use Java FX. These can only be run using Java 8 as Java FX was bundled with it. Newer versions of Java from Oracle do not bundle Java Fx anymore. Therefore, when running the Java income tax utilities, the following error (in red) would appear.
java -jar ITR-1_AY202021_PR2.jar <enter>
Error: Could not find or load main class com.itd.efiling.offline.common.player.ctrl.ThreeRedLightsIlluminate
To set up the Java 8 version as the default Java environment in Fedora Linux, open a linux terminal and run the following command and select Java 8.
sudo update-alternatives --config java <enter>
To install openjfx in Fedora Linux, do following
sudo dnf install java-1.8.0-openjdk-openjfx <enter>
After this, run the income tax java utility again and see if the error went away.