Hi
This issue was caused by the 2017.02 update. It’s now been resolved and if you try and update again in an hour or so you should find that the problem goes away.
I’ve put some more information here if you’d like to expedite this process: Image update error 4.9.29-5 - #4 by sam_nazarko.
It may also be quicker to just download the latest image from Download - OSMC.
Apologies for this!
Cheers
Sam