Hi Alex, I have tested your approach in our system but cannot get it running. So, i have copied following into JIComServer.initialize(...) right before the init() call: super.getProperties().setProperty("rpc.ntlm.seal", "true"); super.getProperties().setProperty("rpc.ntlm.sign", "true"); try{ init(); }catch(JIException e) ... It fails to connect no matter if the hardening introduced by KB5004442 is enabled or not. @Alex could you post you patch, so I could try it with your changes? That would be...