Translations:Dolphin/17/en

Solution: Probably the KDE platform does not know about one of the two filetypes, so it associates the filetype to a different, known filetype. This is common with XML-based filetypes; even if they use a file extension of their own (e.g. .xliff or .graphml), if they are not a filetype known by the KDE platform, they will be treated as any other XML file, and opened with the default application to open XML files.