Upgrade from 4.5 to 4.6 not working

Hi there, I am having a few issues upgrading a wordpress installation. I am moving from 4.5.3 to the latest, 4.6.1 - but every time I try I get an error. I have tried both the auto-update and doing it manually but each time the database appears to become corrupted.

When I did a manual update (copying over the files), I went to login and had a message to update my database. I clicked the ok button and then got the following error.

Can anyone suggest a fix for this?