An error occurred while installing the following package: (unknown package)

Logs here (with debug enabled):

Mar 02 03:02:34 YazPi mediacenter[306]: 2016-03-02 03:02:34.170612 exception value : W:Failed to fetch  Hash Sum mismatch
Mar 02 03:02:34 YazPi mediacenter[306]: , E:Some index files failed to download. They have been ignored, or old ones used instead.

Looks like the Raspbian mirror that you are being directed to (in your country) has problems at the moment. The Pi 1 version of OSMC pulls its main OS packages from the Raspbian APT repository and a number of users have reported issues with this recently.

That’s not a Raspbian mirror, it looks like a Moonlight one

Remove it from sources and re run update

I’ll do that tonight and try the update again, thanks

Sorry for late reply, commenting out that source did the trick, thanks