Konstantin Kolinko

I am also observing this warning, using HSQLDB 2.4.1 in a web application deployed on Apache Tomcat running with OpenJDK 11.0.2. There is a workaround. If I add the following option to Java command line, the warning disappears: --add-opens=java.base/java.nio=ALL-UNNAMED For sake of completeness, I should add that startup scripts of Apache Tomcat also add the following options to the command line. I do not know whether they are important for HSQLDB. (Source code) --add-opens=java.base/java.lang=ALL-UNNAMED...