Hello Syncthing team,
Long time no see, I hope you guys are well 
Thanks for your continuous work on this great software!
I just found a headless Linux (64-bit Intel/AMD) running Syncthing that is stuck on v1.27.12. Log error message: “Automatic upgrade: couldn’t find a release to download”
I tried “wget https://upgrades.syncthing.net/meta.json” - no problems.
Please help me fix this
Thanks and have a nice day!
Are you on an old operating system?
Yeah, it’s an old system. Looking through the release notes but cannot find minimum requirements.
Look for the issue that caused a shitstorm when we last made a release with a new Go compiler. We now enforce those requirements on auto upgrade. You’re welcome. 
You can find the required kernel versions at the bottom of https://github.com/syncthing/syncthing/blob/main/compat.yaml. This is about Go versions used to compile Syncthing, so you would need to check which of them was used to compile the specific Syncthing release.
What is your kernel version though? The minimum was still “2.6.32” (which is very old) until Syncthing v1.29.2 (see also https://docs.syncthing.net/users/releases.html#historical-releases).
Thanks for pointing me in the right direction! 
In GUI it shows “Automatic upgrades - Unavailable/Disabled by administrator or maintainer” and so I was looking for network error, configuration setting, firewall, etc. But instead update check is working correctly - it could be helpful to show a hint e.g. “your system is no longer supported” there?
I will now start cloning myself 
so I can make time to upgrade this old system 
Have a nice day!