TYPO3 Core

i had the same issue as workaround i delete all files in typo3temp (manually).

After that all worked as expected

Ok - sounds interesting.

I haven't done that - as for me it was just a test.
But what I had done was delete all cache data by the install tool.
But what cache files are used here which are not deletable by the install tool? That's strange.

Another case where this fails is openid.

#1433416043: The login provider "1433416748" defines an invalid provider. Ensure the class exists and implements the "TYPO3\CMS\Backend\LoginProvider\LoginProviderInterface" 

Workaround until fixed: delete the typo3temp/autoload/ files

Patch set 2 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/44689