Error while loading shared libraries: libidn.so.11: invalid ELF header?

I am running Ubuntu Mate 16.04 on a Raspberry Pi2.

Mate-terminal and network-manager amongst others have stopped working after updating during a power failure.

Attempting to start either (from tty terminal) gives the error:

error while loading shared libraries: /usr/lib/arm-linux-gnueabihf/libidn.so.11: invalid ELF header

Any idea how I can solve this ? I cannot access any of my networks. Thanks.