MacBook that spontaneously restarts and often shuts down instead of sleeping
I would go for my 'make sure it's all OK' recipe for starters...


Fix permissions [which you did already], Verify &amp; if necessary Repair disk, using Disk Utility
Reset Home folder permissions &amp; ACLs using OnyX  - Maintenance tab/permissions, tick the box at the top then Execute.
Update or [re-apply if already updated] to 10.10.5 using the 10.10.5 combo update, not the delta from App Store