Slim Application Error

The application could not run because of the following error:

Details

Type: ErrorException
Code: 8
Message: Trying to get property of non-object
File: /var/www/vhosts/www/app/controllers/frontend/Range.php
Line: 12

Trace

#0 /var/www/vhosts/www/app/controllers/frontend/Range.php(12): Slim\Slim::handleErrors(8, 'Trying to get p...', '/var/www/vhosts...', 12, Array)
#1 /var/www/vhosts/www/app/controllers/frontend/Range.php(240): get_range_content(Object(Slim\Slim), 'ha-fettige-und-...')
#2 [internal function]: {closure}('de', 'ha-fettige-und-...')
#3 /var/www/vhosts/www/lib/Slim/Route.php(462): call_user_func_array(Object(Closure), Array)
#4 /var/www/vhosts/www/lib/Slim/Slim.php(1326): Slim\Route->dispatch()
#5 /var/www/vhosts/www/lib/Slim/Middleware/Flash.php(85): Slim\Slim->call()
#6 /var/www/vhosts/www/lib/Slim/Middleware/MethodOverride.php(92): Slim\Middleware\Flash->call()
#7 /var/www/vhosts/www/lib/i2N/Middleware/Lang.php(59): Slim\Middleware\MethodOverride->call()
#8 /var/www/vhosts/www/lib/Slim/Extras/Middleware/StrongAuth.php(154): i2N\Middleware\Lang->call()
#9 /var/www/vhosts/www/lib/Slim/Extras/Middleware/StrongAuth.php(77): Slim\Extras\Middleware\StrongAuth->formAuth(Object(Strong\Strong), Object(Slim\Http\Request))
#10 /var/www/vhosts/www/lib/Slim/Middleware/SessionCookie.php(110): Slim\Extras\Middleware\StrongAuth->call()
#11 /var/www/vhosts/www/lib/Slim/Middleware/PrettyExceptions.php(67): Slim\Middleware\SessionCookie->call()
#12 /var/www/vhosts/www/lib/Slim/Slim.php(1271): Slim\Middleware\PrettyExceptions->call()
#13 /var/www/vhosts/www/httpdocs/index.php(219): Slim\Slim->run()
#14 {main}