Ghost and Node 4.x/5.x
Pretty annoying but here is the fix, all credits to https://github.com/vdemedes
Node 5.x
http://blog.z-proj.com/running-ghost-with-node-v5/
Github issue
https://github.com/TryGhost/Ghost/issues/5821
remember to backup first
https://www.allaboutghost.com/how-to-backup-your-ghost-blog/