handle_tcptls_connection: FILE * open failed!

When i enable TSL, it says the following WARNING:

handle_tcptls_connection: FILE * open failed! in a kind of constant loop of about 60 seconds.

Its a self signed certificate, is that the problem?

Should not be a problem. If you temporarily comment a setting in your sip.conf file and the reload the sip in CLI, do you see the following?:

Reloading SIP

== Parsing ‘/etc/asterisk/sip.conf’: Found

== Parsing ‘/etc/asterisk/users.conf’: Found

== Using SIP CoS mark 4

ERROR[19720]: tcptls.c:811 __ssl_setup: TLS/SSL error loading cert file. </etc/asterisk/keys/asterisk.pem>