Looks like something on your PC is messing with your https connections. You can try disabling/uninstalling avast. If you provider is doing this you can try using a VPN.

https://support.avast.com/en-in/article/Use-Antivirus-HTTPS-scan/



I uninstalled avast, it didn't help. I do not have ...

These 520 errors happen when something is wrong in the basic network setup of your PC. It could be Avast messing with https connection from the game client, it could be malfunctioning DNS. There should be a bit more info in the Factorio log file.



Here is the data from the log


17.467 Info ...

viewtopic.php?t=78531


I saw this thread but there is no answer

I can't download mods, when I try to update mod status it gives me an error"API call failed (path: 'api/mods; status: 520)".

How to fix it? Any help.

I have avast and tinywall installed, but I tried adding to exceptions, turning them off and even deleting them - it did not help. So it's not about ...