After finishing the installation of Nextcloud AIO, it is not possible to access it.

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Sorry to hear you’re facing problems. :slightly_frowning_face:

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The Basics

  • Nextcloud Server version (e.g., 29.x.x):
    • Nextcloud AIO v12.5.0
  • Operating system and version (e.g., Ubuntu 24.04):
    • Debian 13 Trixie
  • Web server and version (e.g, Apache 2.4.25):
    *
  • Reverse proxy and version _(e.g. nginx 1.27.2)
    • nginx 1.26.3
  • PHP version (e.g, 8.3):
    *
  • Is this the first time you’ve seen this error? (Yes / No):
    • Yes
  • When did this problem seem to first start?
    • Immediately after installation
  • Installation method (e.g. AlO, NCP, Bare Metal/Archive, etc.)
    • AIO
  • Are you using CloudfIare, mod_security, or similar? (Yes / No)
    • No

Summary of the issue you are facing:

I am having a problem when trying to open Nextcloud AIO. After finishing the installation of the containers, when I click on the “Open your Nextcloud” button, it doesn’t open and a pop-up window appears saying: “Cannot open multiple instances. You can use AIO here by reloading the page.”
To try to fix it, I closed all Nextcloud instances, deleted the cookies, and tried to open Nextcloud in another browser in a private window, but I still can’t get in.

name: nextcloud-aio
services:  
  nextcloud-aio-mastercontainer:    
    image: ghcr.io/nextcloud-releases/all-in-one:latest     
    init: true     
    restart: always     
    container_name: nextcloud-aio-mastercontainer     
    volumes:      
      - nextcloud_aio_mastercontainer:/mnt/docker-aio-config       
      - /var/run/docker.sock:/var/run/docker.sock:ro     
    network_mode: bridge     
    ports:      
      - 12:80       
      - 1234:8080       
      - 5678:8443     
    environment:       
      APACHE_PORT: 11000       
      APACHE_IP_BINDING: 0.0.0.0       
      SKIP_DOMAIN_VALIDATION: true      

volumes:   
  nextcloud_aio_mastercontainer:    
    name: nextcloud_aio_mastercontainer 


server{
    listen 80;
    listen [::]:80;

    server_name mycloud.mynet;

    location / {
        return 301 https://$server_name$request_uri;
    }
}

server {
    listen 443 ssl;
    listen [::]:443 ssl;
    http2 on;

    server_name mycloud.mynet;

    ssl_certificate /etc/letsencrypt/live/mycloud.mynet/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/mycloud.mynet/privkey.pem;
    include /etc/letsencrypt/options-ssl-nginx.conf;
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;

    location / {
        proxy_pass https://127.0.0.1:1234;

        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Port $server_port;
        proxy_set_header X-Forwarded-Scheme $scheme;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header Host $host;
        proxy_set_header Early-Data $ssl_early_data;

        # Websocket
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "Upgrade";
    }
}

Steps to replicate it (hint: details matter!):

  1. Running Docker Compose to install nextcloud-aio-mastercontainer

  2. URL configuration

  3. Installation of the containers

  4. Click on Open your Nextcloud

Log entries

Nextcloud

Please provide the log entries from your Nextcloud log that are generated during the time of problem (via the Copy raw option from Administration settings->Logging screen or from your nextcloud.log located in your data directory). Feel free to use a pastebin/gist service if necessary.

Trying to fix docker.sock permissions internally...
Creating docker group internally with id 989
..+.......+...+..+...+....+..+.+........+.+++++++++++++++++++++++++++++++++++++++++++++*.+..+..................+....+...+...+.....+.+++++++++++++++++++++++++++++++++++++++++++++*........+...........+.+........+.+......+......+.........+........+......+....+...........+......+.+...+.........+..+....+.....+++++
...+..+....+..+++++++++++++++++++++++++++++++++++++++++++++*......+..+....+......+.....+...+.+......+......+..+......+.......+++++++++++++++++++++++++++++++++++++++++++++*....+...+..+.........+................+..........................+.......+..+.+.....+...............+..........+...+......+.....+...+.+......+.....+......+............................+..+.......+..+..........+...........+...+.+.......................+.....................+....+..+...+......+......+.+...+.........+...+...+......+.....+......+.......+...+............+.....+.+.....+...............+....+..+......+.......+........+............+.+...........+...................+.....+.......+...+.....+.....................+++++
-----
Initial startup of Nextcloud All-in-One complete!
You should be able to open the Nextcloud AIO Interface now on port 8080 of this server!
E.g. https://internal.ip.of.this.server:8080
⚠️ Important: do always use an ip-address if you access this port and not a domain as HSTS might block access to it later!

If your server has port 80 and 8443 open and you point a domain to your server, you can get a valid certificate automatically by opening the Nextcloud AIO Interface via:
https://your-domain-that-points-to-this-server.tld:8443
[Thu Feb 05 10:50:34.613884 2026] [mpm_event:notice] [pid 145:tid 145] AH00489: Apache/2.4.66 (Unix) OpenSSL/3.5.4 configured -- resuming normal operations
[Thu Feb 05 10:50:34.613941 2026] [core:notice] [pid 145:tid 145] AH00094: Command line: 'httpd -D FOREGROUND'
[05-Feb-2026 10:50:34] NOTICE: fpm is running, pid 150
[05-Feb-2026 10:50:34] NOTICE: ready to handle connections
{"level":"info","ts":1770288634.6448805,"msg":"maxprocs: Leaving GOMAXPROCS=4: CPU quota undefined"}
{"level":"info","ts":1770288634.6453717,"msg":"GOMEMLIMIT is updated","package":"github.com/KimMachineGun/automemlimit/memlimit","GOMEMLIMIT":7369585459,"previous":9223372036854775807}
{"level":"info","ts":1770288634.645463,"msg":"using config from file","file":"/Caddyfile"}
{"level":"info","ts":1770288634.6470926,"msg":"adapted config to JSON","adapter":"caddyfile"}
{"level":"info","ts":1770288634.6522698,"msg":"serving initial configuration"}
NOTICE: PHP message: Skipping domain validation
Deleting duplicate sessions
NOTICE: PHP message: 404 Not Found
Type: Slim\Exception\HttpNotFoundException
Code: 404
Message: Not found.
File: /var/www/docker-aio/php/vendor/slim/slim/Slim/Middleware/RoutingMiddleware.php
Line: 76
Trace: #0 /var/www/docker-aio/php/vendor/slim/slim/Slim/Routing/RouteRunner.php(62): Slim\Middleware\RoutingMiddleware->performRouting(Object(GuzzleHttp\Psr7\ServerRequest))
#1 /var/www/docker-aio/php/vendor/slim/csrf/src/Guard.php(482): Slim\Routing\RouteRunner->handle(Object(GuzzleHttp\Psr7\ServerRequest))
#2 /var/www/docker-aio/php/vendor/slim/slim/Slim/MiddlewareDispatcher.php(178): Slim\Csrf\Guard->process(Object(GuzzleHttp\Psr7\ServerRequest), Object(Slim\Routing\RouteRunner))
#3 /var/www/docker-aio/php/vendor/slim/twig-view/src/TwigMiddleware.php(117): Psr\Http\Server\RequestHandlerInterface@anonymous->handle(Object(GuzzleHttp\Psr7\ServerRequest))
#4 /var/www/docker-aio/php/vendor/slim/slim/Slim/MiddlewareDispatcher.php(129): Slim\Views\TwigMiddleware->process(Object(GuzzleHttp\Psr7\ServerRequest), Object(Psr\Http\Server\RequestHandlerInterface@anonymous))
#5 /var/www/docker-aio/php/src/Middleware/AuthMiddleware.php(53): Psr\Http\Server\RequestHandlerInterface@anonymous->handle(Object(GuzzleHttp\Psr7\ServerRequest))
#6 /var/www/docker-aio/php/vendor/slim/slim/Slim/MiddlewareDispatcher.php(283): AIO\Middleware\AuthMiddleware->__invoke(Object(GuzzleHttp\Psr7\ServerRequest), Object(Psr\Http\Server\RequestHandlerInterface@anonymous))
#7 /var/www/docker-aio/php/vendor/slim/slim/Slim/Middleware/ErrorMiddleware.php(77): Psr\Http\Server\RequestHandlerInterface@anonymous->handle(Object(GuzzleHttp\Psr7\ServerRequest))
#8 /var/www/docker-aio/php/vendor/slim/slim/Slim/MiddlewareDispatcher.php(129): Slim\Middleware\ErrorMiddleware->process(Object(GuzzleHttp\Psr7\ServerRequest), Object(Psr\Http\Server\RequestHandlerInterface@anonymous))
#9 /var/www/docker-aio/php/vendor/slim/slim/Slim/MiddlewareDispatcher.php(73): Psr\Http\Server\RequestHandlerInterface@anonymous->handle(Object(GuzzleHttp\Psr7\ServerRequest))
#10 /var/www/docker-aio/php/vendor/slim/slim/Slim/App.php(209): Slim\MiddlewareDispatcher->handle(Object(GuzzleHttp\Psr7\ServerRequest))
#11 /var/www/docker-aio/php/vendor/slim/slim/Slim/App.php(193): Slim\App->handle(Object(GuzzleHttp\Psr7\ServerRequest))
#12 /var/www/docker-aio/php/public/index.php(200): Slim\App->run()
#13 {main}
Tips: To display error details in HTTP response set "displayErrorDetails" to true in the ErrorHandler constructor.
Deleting duplicate sessions
Deleting duplicate sessions
Deleting duplicate sessions
Deleting duplicate sessions
nextcloud-aio-domaincheck
Total reclaimed space: 0B
Deleting duplicate sessions

Web Browser

If the problem is related to the Web interface, open your browser inspector Console and Network tabs while refreshing (reloading) and reproducing the problem. Provide any relevant output/errors here that appear.

There are no visible errors

Web server / Reverse Proxy

The output of your Apache/nginx/system log in /var/log/____:

There are no error logs

Configuration

Nextcloud

The output of occ config:list system or similar is best, but, if not possible, the contents of your config.php file from /path/to/nextcloud is fine (make sure to remove any identifiable information!):

Don't know

Apps

The output of occ app:list (if possible).

Tips for increasing the likelihood of a response

  • Use the preformatted text formatting option in the editor for all log entries and configuration output.
  • If screenshots are useful, feel free to include them.
    • If possible, also include key error output in text form so it can be searched for.
  • Try to edit log output only minimally (if at all) so that it can be ran through analyzers / formatters by those trying to help you.
2

Hi, can you follow all-in-one/reverse-proxy.md at main · nextcloud/all-in-one · GitHub?

3

I was able to fix it! I had tried with the Nginx configuration found in “all-in-one/reverse-proxy.md at main · nextcloud/all-in-one · GitHub” and had errors, but the problem was that I was doing it wrong. I tried again after your message and it worked.

Thank you very much.