Slim Application Error

The application could not run because of the following error:
Details
Type: ErrorException
Code: 2
Message: preg_split() expects parameter 2 to be string, array given
File: /web/sites/quill.p3k.io/lib/helpers.php
Line: 145
Trace

#0 [internal function]: Slim\Slim::handleErrors(2, 'preg_split() ex...', '/web/sites/quil...', 145, Array)
#1 /web/sites/quill.p3k.io/lib/helpers.php(145): preg_split('/, ?/', Array)
#2 /web/sites/quill.p3k.io/controllers/auth.php(241): get_syndication_targets(Object(ORM))
#3 [internal function]: {closure}()
#4 /web/sites/quill.p3k.io/vendor/slim/slim/Slim/Router.php(172): call_user_func_array(Object(Closure), Array)
#5 /web/sites/quill.p3k.io/vendor/slim/slim/Slim/Slim.php(1222): Slim\Router->dispatch(Object(Slim\Route))
#6 /web/sites/quill.p3k.io/vendor/slim/slim/Slim/Middleware/Flash.php(86): Slim\Slim->call()
#7 /web/sites/quill.p3k.io/vendor/slim/slim/Slim/Middleware/MethodOverride.php(94): Slim\Middleware\Flash->call()
#8 /web/sites/quill.p3k.io/vendor/slim/slim/Slim/Middleware/PrettyExceptions.php(67): Slim\Middleware\MethodOverride->call()
#9 /web/sites/quill.p3k.io/vendor/slim/slim/Slim/Slim.php(1174): Slim\Middleware\PrettyExceptions->call()
#10 /web/sites/quill.p3k.io/public/index.php(21): Slim\Slim->run()
#11 {main}