Solution for Spotify gray screen

1. Open Terminal app
2. Type this into terminal. By doing this you can open folder with locales:

cd /Applications/Spotify.app/Contents/Resources/locales/

3. Type this into terminal – this deletes all locales because of what Spotify shows gray screen:

rm -rf arb.mo de.mo el.mo es-419.mo es.mo fi.mo fr-CA.mo fr.mo hu.mo id.mo it.mo ja.mo nl.mo pl.mo pt-BR.mo ru.mo sv.mo tr.mo zh-Hant.mo zsm.mo