mr_gorilla11

That's a good pickup, but I did check, and it's on the same custom network, so it's not that. I can reach the login page of the NPM container, just like the other user explained; I just can't actually log in when it's accessed this way. Nothing happens.

I have the same problem. TLDR: I worked around it by using localIP:Port instead of containername:Port under Forward Hostname / IP. I decided to move my NPM setup from the other repo to this official one, so I've started from scratch and configuring my 8 proxies one by one. One of the proxies I have setup is NPM itself, which sends proxy.domain to destination containername:Port, but obviously as I was setting it up, I had to do this through the localIP:Port first. Once I set it up though, I couldn't login to proxy.domain when the proxy was pointing to containername:Port. Same issue as above; nothing happens and the page just sits there with details filled in. I fixed it by changing containername:Port to localIP:Port under Forward Hostname / IP. Not sure if it's the exact same cause as others, because I've only just set it up now, but my setup was (and still is) working fine in my old NPM container, which is running on an older version.

I had this same problem after trying to set up my CyberPower UPS; tried the built in APC UPS daemon, switched to NUT plugin, error message despite daemon being disabled. All I did was set the built in settings to default, and it seems to have stopped throwing error messages now.