I installed the latest livedvd image and updated it.

After that from the dedicated window I opted to install the base KDE components, LibreOffice and VLC.

Thereafter LibreOffice docs or sheets would not open. The error message was not being able to determine the installed language.

The system is installed in American English with Portuguese Brazil (br) keyboard layout.

You can install the Flatpak version of LibreOffice but then it’s necessary to select ‘open with’ every time since the system installed version still tries to open with the same error.

The only solution I can see is not to install LibreOffice from the system options but only the Flatpak version instead.