Shoot… I was really hoping that would fix it.
When the error happens it’s when you first connect (ie: click “Connect”), right?
Another thing you can try is to set the logging level on the server so that it logs every message it sends.
ie: add this to your log4j2.xml (or your server-log4j2.xml if you are running a stand-alone server):
<Logger name="com.jme3.network.base.DefaultServer" level="TRACE" />
Like, to be 100% clear, this is what my log4j.xml file has in it right now:
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="warn" name="MyApp" packages="">
<Appenders>
<RollingFile name="RollingFile" fileName="application.log" ignoreExceptions="false"
filePattern="logs/$${date:yyyy-MM}/application-%d{MM-dd-yyyy}-%i.log.gz">
<PatternLayout>
<Pattern>%d{ABSOLUTE} %-5p [%c{1}] %m%n</Pattern>
</PatternLayout>
<OnStartupTriggeringPolicy />
</RollingFile>
<Console name="STDOUT" target="SYSTEM_OUT" ignoreExceptions="false">
<PatternLayout pattern="%d{ABSOLUTE} %-5p [%c{1}] %m%n"/>
</Console>
</Appenders>
<Loggers>
<Logger name="example" level="DEBUG"/>
<Logger name="com.simsilica.sim" level="TRACE"/>
<Logger name="com.jme3.network.base.DefaultServer" level="TRACE" />
<Root level="INFO">
<AppenderRef ref="RollingFile"/>
<AppenderRef ref="STDOUT"/>
</Root>
</Loggers>
</Configuration>