Solved this this issue - sharing in case helpful
Problem: Lightroom publishing with backlight extremely slow. ( i.e. 1 hour to upload 5 photos)
Sometimes stops altogether with the following error message:
Can’t update this collection.
Error uploading rendition.
Unable to complete the action.
Headers: { [error]=> { [errorCode]=> { “unknown” [name]=> “The connection with the server was terminated abnormally” [nativeCode]=> 12030
}}
Initial findings:
Many 409 errors in web hosting access log.
Further findings by Bluehost tech support:
Provided the publishing URL to Bluehost tech support who determined it was “ blacklisted by Mod security which results in 409 error.”
Resolution-1:
Whitelisting for URL https://[myhost url]/backlight/index.php which had 2 blocks – stopped 409 errors but upload still very slow.
Resolution-2:
- Uninstall ligntroom deleting all settings ( I tried also without deleting settings and that did not help )
- Install light room again – clean. And re-setup Backlight as a plugin.
The above solved the problem. I still do not know what was root cause.
Sharing this as I had tried many other things to try to solve and none helped: clearing lightroom cache, clearing backlight cache, turning off firewall, using different network, reinstalling lightroom without deleting settings, troubleshooting server health with host provider, changing plugin API delay to 1 second – none of these helped.