Hello,
After moving on new server, we gets 500 internal server error at EasyDiscuss pages time to time. it's floating bug, which I cannot reproduce.
There are kind of errors in error.log:

[Mon Mar 16 15:57:36 2015] [error] [client 37.144.113.222] Premature end of script headers: index.php, referer: https://www.mydomain.com/forums/index

Errors are the same, the difference is in URL.

Could you help, please?

Joomla 3.4.0
PHP 5.4.38
MySQL: 5.5.37-MariaDB-wsrep
Fast-CGI (cgi-fcgi)
EasyDiscuss Version: 3.2.9599