[TYPO3-linux] Error installing TYPO3 6.2 beta6

[SVWE]

I try to install latest 6.2 beta6. The install wizard is happy with my enviroment. (1st step)

After clicking next i run into:
Fatal error: Uncaught exception 'TYPO3\CMS\Install\Controller\Exception\RedirectLoopException' with message 'Redirect loop aborted. If this message is shown again after a reload, your setup is so weird that the install tool is unable to handle it. Please make sure to remove the "install[redirectCount]" parameter from your request or restart the install tool from the backend navigation.' in /path/to/typo3_src-6.2.0beta5/typo3/sysext/install/Classes/Controller/AbstractController.php:529 Stack trace:

#0 /path/to/typo3_src-6.2.0beta5/typo3/sysext/install/Classes/Controller/StepController.php(132): TYPO3\CMS\Install\Controller\AbstractController->redirect('', 'databaseConnect')
#1 /path/to/typo3_src-6.2.0beta5/typo3/sysext/install/Classes/Controller/StepController.php(70): TYPO3\CMS\Install\Controller\StepController->outputSpecificStep()
#2 /path/to/typo3_src-6.2.0beta6/typo3/sysext/install/Start/Install.php(134): TYPO3\CMS\Install\Controller\StepController->execute()
#3 {main} thrown in /path/to/typo3_src-6.2.0beta5/typo3/sysext/install/Classes/Controller/AbstractController.php on line 529

URI: typo3test.domain.tld/typo3/sysext/install/Start/Install.php?install[redirectCount]=9&install[context]=standalone&install[controller]=step

After deleting "install[redirectCount]=9" I got the form to enter database informations.

Then clicking next (field filled completely) I got next fatal error:

Fatal error: Class TYPO3\CMS\Install\Controller\Action\Step\DatabaseSelect contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (TYPO3\CMS\Install\Controller\Action\ActionInterface::handle) in /path/to/typo3_src-6.2.0beta6/typo3/sysext/install/Classes/Controller/Action/Step/DatabaseSelect.php on line 33

URI: typo3test.domain.tld/typo3/sysext/install/Start/Install.php?install[redirectCount]=2&install[context]=standalone&install[controller]=step&install[action]=databaseSelect

I have several TYPO3 4.5 installations running on this server/enviroment.

Any Idea to fix this? Maybe a workaround?