Symptoms

After a dist-upgrade Plesk is not accessible:

502 Bad Gateway

On attempt to start sw-engine , the following error message is shown:

# service sw-engine start
sw-engine: symbol lookup error: /usr/lib/x86_64-linux-gnu/liblock_manager.so.2: undefined symbol: _ZNK5boost15program_options29value_semantic_codecvt_helperIcE5parseERNS_3anyERKSt6vectorINSt7__cxx11
12basic_stringIcSt11char_traitsIcESaIcEEESaISB_EEb

# service sw-engine status
-- Unit sw-engine.service has begun starting up.
Oct 28 14:29:28 cloud.contronex.com sw-engine-fpm[22941]: /usr/sbin/sw-engine-fpm: symbol lookup error: /usr/lib/x86_64-linux-gnu/liblock_manager.so.2: undefined symbol: _ZNK5boost15program_options29value_semantic_codecvt_helperIcE5parse
Oct 28 14:29:28 cloud.contronex.com systemd[1]: sw-engine.service: Main process exited, code=exited, status=127/n/a
Oct 28 14:29:28 cloud.contronex.com systemd[1]: Failed to start Startup script for Panel sw-engine.
-- Subject: Unit sw-engine.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit sw-engine.service has failed.

Cause

Plesk packages are broken.

Resolution

1. Download the following packages using wget from here :

       plesk-engine_17.0.17-ubuntu16.04.build1700161005.19_amd64.deb
       plesk-librdbmspp_2.0.1-ubuntu16.04.735641.16061715_amd64.deb
       plesk-lmlib_0.2.2-ubuntu16.04.824.16091218_amd64.deb
       plesk-platform-runtime_1.0.1-ubuntu16.04.892097.16061715_amd64.deb
       sw-cp-server_2.3.0-ubuntu16.04.16072713_amd64.deb
       sw-engine_2.18.9-ubuntu1604.201609121820_amd64.deb
       sw-libpoco_1.4.3p1.1-ubuntu16.04.16061715_amd64.deb
   

2. Download these packages from here :

       sw-libboost-*

3. Reinstall the packages using the command:

   # dpkg -i <.deb file name>
   

4. Start sw-engine :

   # service sw-engine start