Fatal Error after update 2.0 -> 2.1.2

Hi there.
I have a shared server at domainfactory and installed Neos from the d(f backend.
The 2.0 versions runs without problems. So I want to update to 2.1.2 and followed the upgrade instructions from your side.

All worked fine, but the page is not coming back.

I already tried the troubleshootings without success.
Also google did not replied with good results.

Fatal error: Call to undefined method TYPO3\Flow\Resource\Streams\StreamWrapperAdapter::initializeStreamWrapper() in /kunden/xxx/webseiten/subdomain/web/neoscms/Packages/Framework/TYPO3.Flow/Classes/TYPO3/Flow/Core/Booting/Scripts.php on line 524

I’m running php 5.6.16

Any suggestions what I can do?

That looks like the file(s) are not up to date for 2.1.2. The Streamwrapper definitely has the mentiond method in this version.