MainThread#initAWTReflection() uses GlueGen's ReflectionUtil#getMethod(...), whose signature was recently changed to remove an unused ClassLoader. The code in MainThread should be updated to reflect the change. Because the parameter was unused, there should be no harm in simply removing the argument. The corresponding GitHub commit was f92907d. It can be found at: https://github.com/sgothel/gluegen/commit/f92907da4946b29ca3b0132743f1cf0b7d59e080
fixed, you were fast :)