The best way to get the Event Viewer is to go to its
and follow the instructions there.
If using Java, it can be built, or a pre-build jar file can be found in java/jars/java8/JEventViewer-2.0.jar which was built with Java version 8. A jar built with Java 15 can be found in java/jars/java15/JEventViewer-2.0.jar . Easiest of all, it's available for download from this page.