How can I fix the OS X dictionary lookup feature for StackExchange comments in Google Chrome?
I'd be tempted to try the "standard toolkit"…

Do all of these, in this order.


Reset the SMC
As I don't know which Mac you have, read this for instructions for your specific machine - https://support.apple.com/HT201295
Reset the NVRAM
At the boot chimes, hold  Cmd ⌘   Opt ⌥   P   R 
Keep holding all 4 keys until you hear the chimes again, then release.
Fix permissions, Verify &amp; if necessary Repair disk, using Disk Utility
Reset Home folder permissions &amp; ACLs using OnyX  [make sure you get the version appropriate to your OS]  - Maintenance tab/permissions, tick the box at the top then Execute.
Re-apply the 10.10.5 update using the 10.10.5 combo update, not the delta from App Store