Samba suddenly not working anymore

For 2 years now I have been using samba (3.6) on my turris omnia but it is not working anymore.

Neither my windows, nor my Linux clients can connect to it anymore (Ubuntu/Nautilus does not even see it anymore) windows always reports a permission problem (even on public shares) and shares that require a password also fail to work :frowning:

There is also no logging at all from samba, neither at startup nor during the failed connections :frowning: