Error messages in Poedit

Hi all,

when editing existing .po-files of the user manual in German (which are mostly still from 2.7.x releases), I get 2 fatal error messages upon checking/saving in Poedit, saying “This is the location of the first definition” and a duplicate message definition error in the last line.

Note that this occurs even if I only open the file without making any changes and in nearly every file in the DE-directory, and it’s always the last line that is being marked red. However, if I create a new .po-file from the same POT-template, it works fine.

Does anyone else experience this behaviour and how do I get rid of it without having to create a completely new file every time and copy-pasting the strings from the old file?