Update HSQLDB to the latest version
Openfire is using 1.8.0.x, which was last updated in 2008. HSQLDB is currently at 2.3.3.
November 20, 2016, 9:10 PM
Observed this traceback on shutdown with HSQL 2.3.4
January 19, 2016, 2:28 PM
Might be a good task after migrating to Maven.