I have the same issue, but upgrading from 13.0.29 to .33.
It does disable CORE, but I can't reactivate it as it tried to reinstall, and hands out the same error.
I tried updating using fwconsole as suggested when I tried to "Apply Changes" (It also has issues because of core - as can be expected). It seems to be related to Symfony as the web files at the end have a lot of Symfony in them.
From the console I'm getting this:
fwconsole ma install core
Checking if directdids need migrating..already done
updating zap callgroup, pickupgroup..not needed
checking for delay_answer field ..already exists
checking for reversal field ..already exists
checking for pricid field ..already exists
Checking if trunk table migration required..not needed
Checking if privacy manager options exists..already exists
Checking for noanswer_cid field..already exists
Checking for busy_cid field..already exists
Checking for chanunavail_cid field..already exists
Checking for noanswer_dest field..already exists
Checking for busy_dest field..already exists
Checking for chanunavail_dest field..already exists
Unable to add index to extensions field in users
Checking for General Setting migrations..not needed
Deleting unused globals..done
Converting IAX notransfer to transfer if needed..updated 0000 records
deleting obsoleted record_in and record_out entries..ok
checking for dest field in outbound_routes..already exists
checking for continue field in trunks..already exists
upgrading any zap trunks to dahdi if found..ok
[FATAL] you can't convert an existing type, keyword [HTTPBINDPORT]
Trace Back:
/var/www/html/admin/libraries/BMO/Freepbx_conf.class.php:817 die_freepbx()
[0]: you can't convert an existing type, keyword [HTTPBINDPORT]
/var/www/html/admin/modules/core/install.php:1281 FreePBX\Freepbx_conf->define_c onf_setting()
[0]: HTTPBINDPORT
/var/www/html/admin/libraries/modulefunctions.class.php:2388 include_once()
[0]: /var/www/html/admin/modules/core/install.php
/var/www/html/admin/libraries/modulefunctions.class.php:2340 module_functions->_ doinclude()
[0]: /var/www/html/admin/modules/core/install.php
[1]: core
/var/www/html/admin/libraries/modulefunctions.class.php:1896 module_functions->_ runscripts()
[0]: core
[1]: install
/var/www/html/admin/libraries/Console/Moduleadmin.class.php:196 module_functions ->install()
[0]: core
[1]:
/var/www/html/admin/libraries/Console/Moduleadmin.class.php:866 FreePBX\Console\ Command\Moduleadmin->doInstall()
[0]: core
[1]:
/var/www/html/admin/libraries/Console/Moduleadmin.class.php:87 FreePBX\Console\C ommand\Moduleadmin->handleArgs()
/var/www/html/admin/libraries/Composer/vendor/symfony/console/Symfony/Component/ Console/Command/Command.php:257 FreePBX\Console\Command\Moduleadmin->execute()
/var/www/html/admin/libraries/Composer/vendor/symfony/console/Symfony/Component/ Console/Application.php:874 Symfony\Component\Console\Command\Command->run()
/var/www/html/admin/libraries/Composer/vendor/symfony/console/Symfony/Component/ Console/Application.php:195 Symfony\Component\Console\Application->doRunCommand( )
/var/www/html/admin/libraries/Composer/vendor/symfony/console/Symfony/Component/ Console/Application.php:126 Symfony\Component\Console\Application->doRun()
/var/lib/asterisk/bin/fwconsole:132 Symfony\Component\Console\Application->run()