Hello Juha, the error message looks related to the TCP support in core. There was a mismatch in the internal TCP hash table, and it also could not send out a message on a (network) file descriptor. If you only saw it once it is probably not worth to dig that deep into it, might be also caused from some external factors. Cheers, Henning -- Henning Westerholt – https://skalatan.de/blog/ Kamailio services – https://gilawa.com -----Original Message----- From: sr-users &lt;sr-users-bounces(a)lists.kamailio.org&gt; On Behalf Of Juha Heinanen Sent: Thursday, March 12, 2020 9:13 AM To: sr-users(a)lists.kamailio.org Subject: [SR-Users] unknown error messages Any idea where this kind of error message could come from: Mar 12 07:16:17 rox2 /usr/bin/sip-proxy[32058]: CRITICAL: <core> [core/pass_fd.c:277]: receive_fd(): EOF on 61 Mar 12 07:16:17 rox2 /usr/bin/sip-proxy[32058]: ERROR: <core> [core/io_wait.h:607]: io_watch_del(): trying to delete already erased entry 61 in the hash(-1, 0, 0x7f689c16a868) flags 0) Mar 12 07:16:17 rox2 /usr/bin/sip-proxy[32058]: ERROR: <core> [core/io_wait.h:607]: io_watch_del(): trying to delete already erased entry 64 in the hash(-1, 0, 0x7f68c063b0f0) flags 0) Mar 12 07:16:17 rox2 /usr/bin/sip-proxy[32058]: CRITICAL: <core> [core/pass_fd.c:191]: send_fd(): sendmsg failed sending 79 on 64: Broken pipe (32) Mar 12 07:16:17 rox2 /usr/bin/sip-proxy[32058]: ERROR: <core> [core/tcp_main.c:4225]: send2child(): send_fd failed for 0x7f689c18a0b0 (flags 0x4018), fd 79 Debug does not give any hints. -- Juha _______________________________________________ Kamailio (SER) - Users Mailing List sr-users(a)lists.kamailio.org https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users