404 page of TYPO3 results page not found error

Question

I have upgraded my website from TYPO3 9.5 to 10.4. After that my 404-page results in the following Page not found error.

base: /
baseVariants: {  }
errorHandling:
  -
    errorCode: '404'
    errorHandler: Page
    errorContentSource: 't3://page?uid=478'

Answer 1

I found myself a solution by recreating the sites configuration.