TYPO3 Core

Hi,
I just tried to upgrade from 7.6.14 to 8.5 the upgrade itelf worked well and I did all the updates in the install tool including clearing opchache.
I can login and see the changes to the backend, see my pagetree can try out the new form module but when trying to view the page I get the error:

Call to undefined method TYPO3\CMS\Frontend\Controller\TypoScriptFrontendController::getPageRenderer()

more details:
Core: Exception handler (WEB): Uncaught TYPO3 Exception: Call to undefined method TYPO3\CMS\Frontend\Controller\TypoScriptFrontendController::getPageRenderer() | Error thrown in file C:\xampp\xampp706\htdocs\typo3_85_dev\typo3conf\ext\bootstrap_package\Classes\Service\CompileService.php in line 64. Requested URL: http://localhost:88/typo3_85_dev/index.php?id=1

If you need some information or give me a hint on what to look for I can do so. I have a debugging environment running but don't know the coding details.
If I know I can also log on to slack for some chat on the issue if required.
Best regards
Eckard.