Photos on Mac not syncing with iCloud – ThermalPolicy: Must not proceed The Photos app on my Macbook hasn't been syncing for a while, ~6 months. I just came from holidays and added photos from my camera to it and again, nothing. Photos is stuck at "Uploading..." but there is no network activity.

Some facts:


I have a Mid-2014 Macbook Pro
battery health: 82%, cycles: 209, condition: normal
MacOS High-Sierra 10.13.4 (updates in the past didn't help)
I'm on a wired 1gb fiber connection (8ms ping, down: 880, up: 470)
Fully working iCloud photo library across my iOS devices with more than enough free space


What I have tried:


deleting ~/Library/Containers/com.apple.cloudphotosd/Data/Library/Application Support/com.apple.cloudphotosd/ and killing cloudphotosd


It does rebuild the index and re-syncs shared albums, those always work

Resetting the Macbook SMC &amp; PRAM
Fresh install of MacOS, reimport photos from scratch


The actual problem:

The console logs the following which seems highly relevant:

502:com.apple.cloudphotosd.pending-work:509E84:[
    {name: ThermalPolicy, policyWeight: 1.000, response: {Decision: Must Not Proceed, Score: 0.00, Rationale: [{thermalLevel &gt;= 1}]}}
 ], FinalDecision: Must Not Proceed}


Since I have tried so many different software things this makes me think that the system thinks the battery is bust (or some other thermal thing, like CPU temp, which is actually normal ~140F).

Can anyone think of anything else that I should try? Apart from replacing the battery / taking the laptop for service.
The short answer is you want your Mac to get out of CPU use so that iCloud photos will resume. Thermally cooling the case and/or quitting all other processes that use CPU would be warranted.

Since you're technical minded - you can dump the thermal stats to see if you feel you have a hardware issue or can shape the workload to relieve a proper thermal pressure warning:

 pmset -g thermlog


The long answer is there are many throttles and other things that could go wrong with iCloud upload. Look at this reverse engineering of things in the plain files portion of iCloud file upload - let alone the more detailed Photos use that does face, moment, web app and more features in play like daily upload caps, uploads to shared storage being different than your iCloud storage and optimizing the versions when you run low on storage space.



Diagram from the amazing article by Howard Oakley - https://eclecticlight.co/2018/03/30/inside-icloud-drive-uploading-a-file/