[SOLVED] NC28 AIO: "This server has no working internet connection:" after reboot

AIO 8.2.1 running as a Proxmox (8.2.2, latest) LXC for almost a year.

After reboot, I’m getting “This server has no working internet connection: Multiple endpoints could not be reached.” and “Could not check for JavaScript support. Please check manually if your webserver serves .mjs files using the JavaScript MIME type.”

I CAN access NC GUI and open files remotely from outside the LAN. I CAN NOT open OpenOffice documents. I also cannot open the AIO interface now.

There was no Proxmox or Nextcloud update in the meantime. The only thing I noticed is my ISP changing IP of their DNS server (I see this on my router).

  • rebooting everything did not help
  • I have Nginx Proxy Server in front of NC
  • IPs are fine (static, reserved on router)
  • config.php contains this:
  'trusted_proxies' => 
  array (
    0 => '',
    1 => '::1',
    2 => '',
    10 => '',

where 106 is the Nginx Proxy.

  • I can ping from the LXC, I can NOT ping my domain (nc.MYDOMAIN.cz) nor any other domain. Only IPs.
  • NC logs shows many errors like
cURL error 6: Could not resolve host: www.nextcloud.com (see https://curl.haxx.se/libcurl/c/libcurl-errors.html) for http://www.nextcloud.com/

Please advise. Thanks.

SOLUTION: I have installed Tailscale on the Proxmox host, which changed its DNS to (their DNS server). After changing that to my router’s and Google’s, stuff resolves fine again and there’s no error in NC. Apparently I haven’t rebooted since I installed TS, so their DNS only got into effect after today’s reboot. I will only install Tailscale onto guests from now.

Yes, another “it’s always DNS” thing.