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Pixel~by~Pixel
Pixel~by~Pixel
Participant
Nov 10, 2026 9:54 AM UTC
Question

problem uploading from classic to cloud

Subject: Lightroom Classic won't sync ~40 photos with AI edits - AuxMissingError 403

Hello,

I'm on the Photography plan (1TB), Lightroom Classic on Mac, syncing to Lightroom on iPhone 15 Pro and iPad.

About 40 photos will not upload to Lightroom cloud. They all have AI-related edits (Remove tool / Generative Remove or AI masks). My sync diagnostic log shows this on the develop settings upload (xmp/develop/parts) to storage.adbephotos.com:

HTTP 403, code and subtype "AuxMissingError": "Some of the aux files are not uploaded which is required for rendition generation."

I've tried: pause and resume, restarting Classic, Update AI Settings, and Rebuild Sync Data. None fixed it. Taking the failing photos out of sync let the other ~600 photos upload normally. 34 other photos with AI edits did upload fine, so it isn't every AI photo.

My log also shows a database error in the AI mask data file on 5 November (it looks healthy now), so I can't tell whether this is a server issue or damaged local mask data.

I need these photos synced with their edits intact and editable on all my devices, without flattening them to JPEGs. Has anyone seen this, or can an Adobe team member look into it? I can share the full sync diagnostic log.

Lightroom Classic version: 15.6

Thank you.

    1 reply

    Sameer K
    Community Manager
    Sameer KCommunity Manager
    Community Manager
    Nov 10, 2026 1:41 PM UTC

    Hey, @Pixel~by~Pixel. Welcome to the Lightroom Classic Community. Lightroom Classic v16 is arriving very soon. If you already have an update, please update and let Lightroom Classic sync for at least an hour or two before making any changes.


    Lightroom Classic does not sync directly with Lightroom Mobile; you'll have to check Lightroom Web (https://adobe.ly/4eF2E7u)


    In Lightroom Web (https://adobe.ly/4eF2E7u), look for the Deleted Section and the Sync issues tab (if they exist). Emptying both of these has helped in the past. Before emptying these tabs, please ensure you have backups for the images.


    The error code suggests that the files are missing or unreachable. In Lightroom Classic, go to Library > Library (top menu) > Find All Missing Photos. A Category for Missing images will appear in the left rail in the Catalog panel if it does not exist already. Here, check whether any of the missing images are also the ones not syncing.

     

    After this change, let Lightroom sync and check if it returns to normal.

    Thanks!

    Sameer K

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