Had the same problem. Hadn't sync my wallet for about a month (I had 1.0.11). Tried lots of times to get it to fully sync (deleted entire blockchain [everything in the appData/Roaming/ZCash folder EXCEPT wallet.dat and peers.dat] and tried re-syncing from the very beginning) but nothing would stop me getting an error when the blockchain was trying to sync past 19th Dec 2017.

Finally uninstalled 1.0.11 and installed 1.0.12 and it is working fine now. Fully synced to the network.

That might be the date the newer version was released but I am not sure. Anyway, synving as far as I could with the old version, uninstalling, and installing 1.0.12 worked perfectly, so hopefully this might help someone having a similar problem.