Whoops\Exception\ErrorException Illegal string offset 'srvip' Endpoint Manager won't install

First attempt: it was downloaded but not installed locally. Trying to install got a similar error, illegal string offset 'disable_epm' at line 86 of Endpointman.class.php. Commenting that line as an experiment, gave same error at line 94. Commenting that also, the install completed however, I then got the following from fwconsole reload --verbose :

Whoops\Exception\ErrorException: Methods with the same name as their class will not be constructors in a future version of PHP; gui_link_nw_tab has a deprecated constructor in file /var/www/html/admin/modules/e ndpointman/functions.inc.php on line 284
Stack trace:
1. Whoops\Exception\ErrorException->() /var/www/html/admin/modules/endpointman/functions.inc.php:284
2. Whoops\Run->handleError() /var/www/html/admin/bootstrap.php:353
3. require_once() /var/www/html/admin/bootstrap.php:353
4. require_once() /etc/freepbx.conf:9
5. include_once() /var/lib/asterisk/bin/fwconsole:12
root@cem01vpbx:/var/www/html/admin/modules/endpointman# fwconsole reload --verbose
Whoops\Exception\ErrorException: Methods with the same name as their class will not be constructors in a future version of PHP; gui_link_nw_tab has a deprecated constructor in file /var/www/html/admin/modules/endpointman/functions.inc.php on line 284
Stack trace:
1. Whoops\Exception\ErrorException->() /var/www/html/admin/modules/endpointman/functions.inc.php:284
2. Whoops\Run->handleError() /var/www/html/admin/bootstrap.php:353
3. require_once() /var/www/html/admin/bootstrap.php:353
4. require_once() /etc/freepbx.conf:9
5. include_once() /var/lib/asterisk/bin/fwconsole:12

Therefore I uninstalled and removed Endpoint Manager (OSS) completely, and tried to download and install again. I received the following:

Whoops\Exception\ErrorException thrown with message "Illegal string offset 'srvip'"

Stacktrace:
#9 Whoops\Exception\ErrorException in /var/www/html/admin/modules/endpointman/lib/Config.class.php:25
#8 Whoops\Run:handleError in /var/www/html/admin/modules/endpointman/lib/Config.class.php:25
#7 FreePBX\modules\Endpointman\Config:getConfigModuleSQL in /var/www/html/admin/modules/endpointman/lib/Config.class.php:17
#6 FreePBX\modules\Endpointman\Config:__construct in /var/www/html/admin/modules/endpointman/Endpointman.class.php:81
#5 FreePBX\modules\Endpointman:__construct in /var/www/html/admin/libraries/BMO/Self_Helper.class.php:124
#4 FreePBX\Self_Helper:autoLoad in /var/www/html/admin/libraries/BMO/Self_Helper.class.php:63
#3 FreePBX\Self_Helper:injectClass in /var/www/html/admin/libraries/modulefunctions.class.php:2560
#2 module_functions:_runscripts in /var/www/html/admin/libraries/modulefunctions.class.php:2034
#1 module_functions:install in /var/www/html/admin/page.modules.php:194
#0 include in /var/www/html/admin/config.php:476

The module now shows as Not Installed (Locally available: 14.0.2.1) and attempting to install returns the same Whoops as immediately above (which is the issue subject)

Conclusion, Endpoint Manager OSS will not install on Framework 15.0.16.49