HyperV

Well, it's the docker hub registry that changed something. However, the HTTP RFC spec states headers are case-insensitive, so the script is at fault and this script is under the control of LT. Unfortunately this temporary fix is indeed volatile, it will not survive a reboot. The script is unpacked from the image files to ram on each boot. A permanent fix would have to be made by LT. However, as @Squid pointed out, the current source of the webgui of Unraid, which contains this script, already has updated code for this. It appears someone else at some point revisited the code and came to the conclusion as well that the code was faulty and that headers should be checked case-insentively before this ever became a real problem. Now it has actually become a problem for people still running older versions because the casing of the header changed, so this fix should probably be back-ported or we are stuck with this temporary solution.

Good to know this has been fixed already in later versions 👍

I had exactly the same issue and could not find any solutions on the forum or the internet. So I did some digging myself and found the cause of the issue. The docker update check script gets the remote digest of the latest tag from the docker repository via a header called 'Docker-Content-Digest'. The script checks for this header with a case-sensitive regex pattern. Manually querying the docker hub registry gives me a header called 'docker-content-digest' (mind the casing). The docker hub registry must have recently changed the casing of this header, because it broke for me in the last 24 hours. I'm running on Unraid 6.8.3 still, so I'm not 100% sure if this issue also exists in 6.9.x. If you feel up to it, you could quite easily fix this yourself until there is a real fix. I'll describe the steps below: Open file: /usr/local/emhttp/plugins/dynamix.docker.manager/include/DockerClient.php Go to line 457. There you should look for the text: @Docker-Content-Digest:\s*(.*)@ and replace it with: @Docker-Content-Digest:\s*(.*)@i Save the file. This will make the header check case-insensitive and should make it work again.