TYPO3 Core

Usecase:

I got a website, updating from 11 to 13, then I changed to use PAGEVIEW and now I move content elements around because those used a (for me wrong) structure. Templates files moved around but its configuration still missing => getting exception

PAGEVIEW TypoScript object: Failed to resolve the expected template file "Pages/Tabs.html" for layout "Tabs". See also: https://docs.typo3.org/permalink/t3tsref:cobj-pageview@13.4. The following paths were checked: EXT:theme/Resources/Private/Page/Pages/Tabs.html

but the exception is about content elements! the exeption message would tell me

Headerkeyvisual" in format ".html", but none of the paths contained the expected template file (Default/Headerkeyvisual.html). The following paths were checked: /var/www/html/app/site/vendor/typo3/cms-fluid-styled-content/Resources/Private/Templates/, /var/www/html/app/site/vendor/studiomitte/theme/Resources/Private/Templates/Content/

but this is not outputted and also should not be caught by pageview