[TYPO3-Solr] indexing failes because of no real frontend user

[Rolf Nakielski]

Hi,
I use tx_solr 3.0 and TYPO3 6.11. Searching and indexing runs very well - great extension.

Exept there is one page that always fails. On this page I use a plugin from my own extbase extension. 
In the controller I check whether an frontent user is logged in by:

if ((int)$GLOBALS['TSFE']->loginUser === 1)
    $user = $this->userRepository->findByUid($GLOBALS['TSFE']->fe_user->user['uid']);
    $demand->setEmail($feuser->getEmail());
    ...
}

This works very well in the normal frontend. But when the page is indexed it failes. 
The condition: "$GLOBALS['TSFE']->loginUser" is true but no user can be found using $GLOBALS['TSFE']->fe_user->user['uid'].

So I get a fatal PHP error: "Call to a member function getEmail() on a non-object" and tx_solr logs an Internal Server Error.

It seems that during Indexing tx_solr pretends to have a user loggd in that does not exist? 

Is there any hint for me?