[OpenSIPS-Users] Failed INVITE tcp_send

[opensipslist at encambio.com]

Hello list,

REGISTER messages seem to be handled correctly, but I'm still having
troubles with INVITEs:

  Dec 16 19:03:05 name.host.tld <error> opensips[10237]: ERROR:core:tls_blocking_write: too many retries with no operation
  Dec 16 19:03:05 name.host.tld <error> opensips[10237]: ERROR:core:tcp_send: failed to send
  Dec 16 19:03:05 name.host.tld <error> opensips[10237]: ERROR:tm:msg_send: tcp_send failed
  Dec 16 19:03:05 name.host.tld <error> opensips[10237]: ERROR:tm:t_forward_nonack: sending request failed
  Dec 16 19:03:05 name.host.tld <error> opensips[10237]: ERROR:core:tls_accept: some error in SSL (ret=0, err=5, errno=0/Error 0):

Where can I find out what 'err=5' means regarding SSL, and what does
this typically mean? I'm pretty sure that my certs are in order,
because this opensips.cfg was working in OpenSER 1.3.X as is.

Thanks,
Brian