Thanks Michael. I downloaded the flite 2.0 from http://files.freeswitch.org/downloads/libs/flite-2.0.0.tar.gz and build it as below ./configure --enable-sharedmakemake install build and run freeswitch-1.8, the same error occurred again. However mod_flite was successfully loaded if I ran freeswitch as below (used LD_PRELOAD to load libflite_cmulex) kxie@kxie-Inspiron-3656:~/freeswitch-install$ pwd/home/kxie/freeswitch-installkxie@kxie-Inspiron-3656:~/freeswitch-install$ LD_PRELOAD=/usr/local/lib/libflite_cmulex.so ./bin/freeswitch /Kaiduan On Tuesday, September 4, 2018, 12:32:54 PM EDT, Michael Jerris <mike@jerris.com> wrote: Our build requires flite 2.0 …. Our latest Debian unstable and 1.8 repos have these packages, for ubuntu you likely need to build these packages yourself from our support deps in stash. On Sep 3, 2018, at 12:26 PM, kaiduan xie via FreeSWITCH-users <freeswitch-users@lists.freeswitch.org> wrote: From: kaiduan xie <kaiduanx@yahoo.ca> Subject: mod_flite fails due to undefined symbol: cmu_lex_init Date: August 30, 2018 at 7:10:06 PM EDT To: FreeSWITCH Users Help <freeswitch-users@lists.freeswitch.org> Hi all, I build and run FreeSwitch 1.6.20 from source on Ubuntu 16.0.4 xenial, the mod_filte failed while loading, 2018-08-30 19:03:30.786468 [CRIT] switch_loadable_module.c:1522 Error Loading module /home/kxie/freeswitch-dev-install/lib/freeswitch/mod/mod_flite.so**/usr/local/lib/libflite_cmu_us_slt.so.1: undefined symbol: cmu_lex_init** Any idea to solve this issue? Many thanks, /Kaiduan _________________________________________________________________________ Professional FreeSWITCH Services sales@freeswitch.com https://freeswitch.com Official FreeSWITCH Sites https://freeswitch.com/oss https://freeswitch.org/confluence https://cluecon.com FreeSWITCH-users mailing list FreeSWITCH-users@lists.freeswitch.org http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users https://freeswitch.com