Splunk MINT: Why am getting crash error "com/splunk/mint/network/socket/close" invoked from socket/accept?

[wwwyw]

Recently, I received many crashed errors like below:

 java.lang.NullPointerException
at com.splunk.mint.network.MonitorRegistry.getMetricsForName(MonitorRegistry.java:31)
at com.splunk.mint.network.socket.MonitoringSocketImpl.close(MonitoringSocketImpl.java:199)
at java.net.Socket.close(Socket.java:317)
at java.net.ServerSocket.accept(ServerSocket.java:130)
....

[croyal_splunk]

The fix for the NullPointerException issue was released in 5.x SDK version.