While I've been trying to resolve my issue regarding crashing on wake from hibernation I've discovered that my MAC Air states that it can not sleep properly due to "Address Book Source Sync" happening. If I do a pmset -g assertions I see that the pid for AddressBookSourceSync changes every 30seconds and it continues indefinitely. I've tried numerous attempted resolutions from google search which includes deleteing the cache and the actual contacts database however even with these removed it appears that this process keeps running indefinitely forever. The only way that it seems to disappear is if i enable icloud and sync contacts. Then it is happy. However, as soon as I disable iCloud by log out the issue returns. This only started happening when i went to ElCap and I'm now almost at my wits end with El Cap and going to head back to Yosemite due to the El Cap issues (this and crash from sleep). Any help appreciated on how to stop el cap \demanding that it has to sync to icloud to go to sleep.