Filemanager 500 Error in 2.6.0

[nickian]

What type of report is this:

Q	A
Bug report?	Yes
Feature request?	No
Enhancement?	No

Description:

After updating to 2.6.0, the Filemanager has become inaccessible. It just sits at the initial loading screen and generates a 500 error in the console.

If a bug:

Q	A
Mautic version	2.6.0
PHP version	7.0.14

Steps to reproduce:

1. Be logged in.
2. Open the filemanager (https://mautic.mysite.com/app/bundles/CoreBundle/Assets/js/libraries/ckeditor/filemanager/index.html?type=Images)

Log errors:

Chrome console: jquery-1.11.3.min.js:5 GET https://mautic.mysite.com/app/bundles/CoreBundle/Assets/js/libr…lemanager.php?path=%2F&mode=getfolder&showThumbs=true&time=899&type=Images 500 (Internal Server Error)

Apache error.log:

[Mon Feb 13 14:07:07.156641 2017] [:error] [pid 3167] [client 0.0.0.0:64572] PHP Fatal error:  Uncaught Symfony\\Component\\Debug\\Exception\\FatalThrowableError: Call to a member function setLogger() on null in /home/mautic/www/app/bundles/CoreBundle/EventListener/ErrorHandlingListener.php:42

\nStack trace:

\n#0 /home/mautic/www/app/cache/prod/appProdProjectContainer.php(5984): Mautic\\CoreBundle\\EventListener\\ErrorHandlingListener->__construct(Object(Symfony\\Bridge\\Monolog\\Logger), Object(Symfony\\Bridge\\Monolog\\Logger), NULL)

\n#1 /home/mautic/www/vendor/symfony/dependency-injection/Container.php(314): appProdProjectContainer->getMautic_Core_Errorhandler_SubscriberService()

\n#2 /home/mautic/www/vendor/symfony/event-dispatcher/ContainerAwareEventDispatcher.php(183): Symfony\\Component\\DependencyInjection\\Container->get('mautic.core.err...')

\n#3 /home/mautic/www/vendor/symfony/event-dispatcher/ContainerAwareEventDispatc in /home/mautic/www/app/bundles/CoreBundle/EventListener/ErrorHandlingListener.php on line 42, referer: https://mautic.mysite.com/app/bundles/CoreBundle/Assets/js/libraries/ckeditor/filemanager/index.html?type=Images

[escopecz]

Duplicate of https://github.com/mautic/mautic/issues/3381