Hello. We have received a report showing the following error message: Tue May 15 08:25:49 2018 : Error: Failed binding to auth+acct address 192.168.1.36 port 2083 (TLS) bound to server default: Bad file descriptor Tue May 15 08:25:49 2018 : Error: \freeradius-server-3.0.16\etc\raddb/sites-enabled/tls[7]: Error binding to port for 192.168.1.36 port 2083 The IP address shown above is valid. Digging a bit in the code base (listen.c) has led us to the following line: #ifdef HAVE_PTRHEAD_H After fixing that, now we see (radiusd -Xxx): Tue May 15 10:16:50 2018 : Error: \freeradius-server-3.0.16\etc\raddb/sites-enabled/tls[7]: Threading must be enabled for TLS sockets to function properly Tue May 15 10:16:50 2018 : Error: \freeradius-server-3.0.16\etc\raddb/sites-enabled/tls[7]: You probably need to do 'radiusd -fxx -l stdout' for debugging Running 'radiusd -fxx -l stdout' shows: ... ... ... Listening on auth+acct proto tcp address 192.168.1.36 port 2083 (TLS) bound to server default Listening on auth address * port 1812 bound to server default Listening on acct address * port 1813 bound to server default Listening on auth address :: port 1812 bound to server default Listening on acct address :: port 1813 bound to server default Listening on auth address 192.168.1.36 port 1821 bound to server example Listening on auth address 127.0.0.1 port 18120 bound to server inner-tunnel Listening on status address 127.0.0.1 port 18121 bound to server status Listening on proxy address * port 54433 Listening on proxy address :: port 54434 Ready to process requests We are not familiar with TLS but the message: 'Threading must be enabled for TLS sockets to function properly' seems misleading. Any help would be appreciated. Thanks in advance.