Doesn't recognize ODF files without file extension

[TomTasche]

If you upload an ODF file without file extension to iCloud Drive, it'll show up greyed-out in the app. After renaming it to add a file extension the file will work fine.

[TomTasche]

@Metaxa007 says this is not reproducible. Need to test again

[TomTasche]

I can still reproduce this by uploading an odt-file without file extension via the iCloud web interface: https://www.icloud.com/iclouddrive/