openSER crashes at startup

When starting openSER at the command line or as a service I get the following error 80% of the time. Normally I have to make a few attempts (type 'openser' and hit enter) before it starts up.

Apr 7 16:55:15 [12653] ERROR:core:io_watch_add: epoll_ctl failed: Invalid argument [22]
Apr 7 16:55:15 [12653] CRITICAL:core:tcp_main_loop: failed to add process 18 (TCP main) unix socket to the fd list
Apr 7 16:55:15 [12653] CRITICAL:core:tcp_main_loop: exiting...Apr 7 16:55:15 [12635] INFO:core:handle_sigs: child process 12653 exited normally, status=255
Apr 7 16:55:15 [12635] INFO:core:handle_sigs: terminating due to SIGCHLD
Apr 7 16:55:15 [12637] INFO:core:sig_usr: signal 15 received
Memory status (pkg):