Guacamole: How to fix RDP server closed/refused connection: Security negotiation failed (wrong security type?)

This short tutorial shows you how to fix RDP server closed/refused connection: Security negotiation failed (wrong security type?) error while connecting to Windows systems using Apache Guacamole.

Guacamole: How to fix RDP server closed/refused connection: Security negotiation failed (wrong security type?)

Sample syslog error logs on Apache Guacamole Server;

Apr  9 18:05:25 Ubuntu20.04 guacd[54811]: RDP server closed/refused connection: Security negotiation failed (wrong security type?)
Apr  9 18:05:25 Ubuntu20.04 guacd[54811]: guacd[54811]: INFO:#011RDP server closed/refused connection: Security negotiation failed (wrong security type?)

tail -f /var/log/messages

Or

tail -f /var/log/syslog

Apr  9 18:05:24 Ubuntu20.04 guacd[54811]: FreeRDP initialization may fail: The current user's home directory ("/usr/sbin") is not writable, but FreeRDP generally requires a writable home directory for storage of configuration files and certificates.
Apr  9 18:05:24 Ubuntu20.04 guacd[54811]: guacd[54811]: WARNING:#011FreeRDP initialization may fail: The current user's home directory ("/usr/sbin") is not writable, but FreeRDP generally requires a writable home directory for storage of configuration files and certificates.
Apr  9 18:05:24 Ubuntu20.04 guacd[54811]: No security mode specified. Defaulting to security mode negotiation with server.
Apr  9 18:05:24 Ubuntu20.04 guacd[54811]: guacd[54811]: INFO:#011No security mode specified. Defaulting to security mode negotiation with server.
Apr  9 18:05:24 Ubuntu20.04 tomcat9[52647]: 18:05:24.829 [http-nio-8080-exec-8] INFO  o.a.g.tunnel.TunnelRequestService - User "guacadmin" connected to connection "1".
...
...
...
Apr  9 18:05:24 Ubuntu20.04 guacd[54811]: guacd[54811]: INFO:#011Resize method: none
Apr  9 18:05:24 Ubuntu20.04 guacd[54811]: guacd[54811]: INFO:#011No clipboard line-ending normalization specified. Defaulting to preserving the format of all line endings.
Apr  9 18:05:24 Ubuntu20.04 guacd[54811]: guacd[54811]: INFO:#011User "@d76510c0-0ff2-4561-b4dd-742da0c7518b" joined connection "$81e5c9d8-1143-4893-9f25-c41563e276c0" (1 users now present)
Apr  9 18:05:24 Ubuntu20.04 guacd[54811]: guacd[54811]: INFO:#011Loading keymap "base"
Apr  9 18:05:24 Ubuntu20.04 guacd[54811]: guacd[54811]: INFO:#011Loading keymap "en-us-qwerty"
Apr  9 18:05:24 Ubuntu20.04 rsyslogd: action 'action-7-builtin:omfile' suspended (module 'builtin:omfile'), retry 0. There should be messages before this one giving the reason for suspension. [v8.2001.0 try https://www.rsyslog.com/e/2007 ]
Apr  9 18:05:24 Ubuntu20.04 rsyslogd: action 'action-7-builtin:omfile' suspended (module 'builtin:omfile'), next retry is Sat Apr  9 18:05:54 2022, retry nbr 0. There should be messages before this one giving the reason for suspension. [v8.2001.0 try https://www.rsyslog.com/e/2007 ]
Apr  9 18:05:24 Ubuntu20.04 guacd[54811]: Resize method: none
Apr  9 18:05:24 Ubuntu20.04 guacd[54811]: No clipboard line-ending normalization specified. Defaulting to preserving the format of all line endings.
Apr  9 18:05:24 Ubuntu20.04 guacd[54811]: User "@d76510c0-0ff2-4561-b4dd-742da0c7518b" joined connection "$81e5c9d8-1143-4893-9f25-c41563e276c0" (1 users now present)
Apr  9 18:05:24 Ubuntu20.04 guacd[54811]: Loading keymap "base"
Apr  9 18:05:24 Ubuntu20.04 guacd[54811]: Loading keymap "en-us-qwerty"
Apr  9 18:05:25 Ubuntu20.04 guacd[54811]: RDP server closed/refused connection: Security negotiation failed (wrong security type?)
Apr  9 18:05:25 Ubuntu20.04 guacd[54811]: guacd[54811]: INFO:#011RDP server closed/refused connection: Security negotiation failed (wrong security type?)
Apr  9 18:05:25 Ubuntu20.04 guacd[54811]: User "@d76510c0-0ff2-4561-b4dd-742da0c7518b" disconnected (0 users remain)
Apr  9 18:05:25 Ubuntu20.04 tomcat9[52647]: 18:05:25.164 [http-nio-8080-exec-7] INFO  o.a.g.tunnel.TunnelRequestService - User "guacadmin" disconnected from connection "1". Duration: 333 milliseconds
Apr  9 18:05:25 Ubuntu20.04 guacd[54811]: guacd[54811]: INFO:#011User "@d76510c0-0ff2-4561-b4dd-742da0c7518b" disconnected (0 users remain)
Apr  9 18:05:25 Ubuntu20.04 guacd[54811]: guacd[54811]: INFO:#011Last user of connection "$81e5c9d8-1143-4893-9f25-c41563e276c0" disconnected
Apr  9 18:05:25 Ubuntu20.04 guacd[54811]: Last user of connection "$81e5c9d8-1143-4893-9f25-c41563e276c0" disconnected
Apr  9 18:05:25 Ubuntu20.04 guacd[25527]: Connection "$81e5c9d8-1143-4893-9f25-c41563e276c0" removed.
Apr  9 18:05:25 Ubuntu20.04 guacd[25527]: guacd[25527]: INFO:#011Connection "$81e5c9d8-1143-4893-9f25-c41563e276c0" removed.
Apr  9 18:05:25 Ubuntu20.04 tomcat9[52647]: Exception in thread "Thread-14" java.lang.IllegalStateException: Message will not be sent because the WebSocket session has been closed

In order to fix the errors

Apr  9 18:05:25 Ubuntu20.04 guacd[54811]: RDP server closed/refused connection: Security negotiation failed (wrong security type?)
Apr  9 18:05:25 Ubuntu20.04 guacd[54811]: guacd[54811]: INFO:#011RDP server closed/refused connection: Security negotiation failed (wrong security type?)

And allow you to access Windows system via Apache Guacamole, check out this tutorial;

How to fix RDP server closed/refused connection: Security negotiation failed (wrong security type?)

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