[TYPO3-dev] TYPO3 7.0.2: Cannot connect to signalSlot

[Thomas Hucke]

Hi list,

I try to connect my extension to a signalslot. So according to the 
documentation I found I added the following code to my ex_localconf.php:

$objectManager = 
\TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance('TYPO3\\CMS\\Extbase\\Object\\ObjectManager');
$signalSlotDispatcher = 
$objectManager->get('TYPO3\\CMS\\Extbase\\SignalSlot\\Dispatcher');
$signalSlotDispatcher->connect('Thucke\\ThRating\\Controller\\VoteController', 
'beforeCallActionMethod', 'Thucke\\ThRating\\Controller\\VoteController', 
'emitBeforeCallActionHandler',FALSE);

After flushing all caches the following error occurs in FE and BE:
Fatal error: Call to a member function exec_SELECTgetSingleRow() on a 
non-object in 
N:\xampp\htdocs\TYPO3\typo3_src-7.0.2\typo3\sysext\core\Classes\Cache\Backend\Typo3DatabaseBackend.php 
on line 172
Obviously the issue is caused by second line calling the get-Method of the 
objectManager.

Is it a bug?
Any idea?

Thanks in advance.

Thomas