@DavidCarlisle Another thing I read above your conversation with @UlrikeFischer: There is also an outdated colortbl-de, but this is already in the package of this author who must not be named (or was it blamed?).
And there is another outdated package etoolbox-de https://ctan.org/pkg/etoolbox-de which is not packed into MiKTeX (but apprently into TL).
And there is another outdated package etoolbox-de https://ctan.org/pkg/etoolbox-de which is not packed into MiKTeX (but apprently into TL).