With TYPO3 9.5.17, I have an error, when adding a file or image upload field to ext:form. Also, the error occurs, when trying to edit a form with such a field through backend UI. Oops! Something went wrong. Please contact your administrator. Technical Reason: Invalid parameter "key" (1475361755) !Bildschirmfoto 2020-05-12 um 16.05.24.png! (see attached screenshot). With TYPO3 9.5.16 everything works fine.