The client code has a "com.sun.awt.SecurityWarning" class which at some point in the past, JDK 6u10, was used as a kind of "public" API. During development of jdk9 it was considered that this API is not supported and may be removed in the future: https://bugs.openjdk.java.net/browse/JDK-8051640.
This class was deprecated forRemoval=true in JDK 11 (https://bugs.openjdk.java.net/browse/JDK-8205588). This class is unused in the JDK and can be removed.
The solution is to remove: