The previous release candidate was compiled with the class file version 53.0 instead of 50.0. Therefore, the second release candidate could only run on Java 9 and later. However, the third release candidate is again compiled with the class file version 50.0 and also runs on Java 6-8. Thanks to MairwunNx for reporting this issue.
Third release candidate of tinylog 2.1 is out
February 18, 2020