Troubleshooting

Docker is not running

failed to connect to the docker API at unix:///…/docker.sock; check if the path is correct and if the daemon is running

Older Docker versions say "Cannot connect to the Docker daemon" instead. Either way, the Docker engine is not started.

1. 01

   Open Docker Desktop

   Start Docker Desktop and wait until it reports that the engine is running. On Linux, start the service: sudo systemctl start docker.
2. 02

   Check that Docker answers

   TerminalCopy

   docker info

   Expected result: It prints a Server section instead of an error.
3. 03

   Run your command again

   docker build -t publino-landing ., then docker run -p 3030:3030 publino-landing.

A port is already in use

Bind for 0.0.0.0:3030 failed: port is already allocated
ports are not available: exposing port TCP 0.0.0.0:3030 … bind: address already in use
Error: listen EADDRINUSE: address already in use :::3030

The first two lines come from Docker, the last from yarn dev or yarn start. Another program already listens on port 3030: often an earlier run of this site, or another project's server.

1. 01

   Find what holds the port

   On macOS or Linux:

   TerminalCopy

   lsof -i :3030

   On Windows, in PowerShell:

   TerminalCopy

   netstat -ano | findstr :3030
2. 02

   Stop it

   Close that program, or stop the earlier run: Ctrl+C in its terminal, or docker stop with the container's ID from docker ps. Then start the site again.
3. 03

   Or use another port

   Keep the other program and start the site on a free port, here 3041:

   How you run it	Command
   Docker	docker run -p 3041:3030 publino-landing
   Development server	yarn dev -p 3041
   Production build	yarn start -p 3041

   With Docker, change only the number on the left of -p: the site inside the container always listens on 3030.

   Expected result: The site answers on localhost:3041Local.

The build fails

docker build stops with "failed to solve" and the step that failed; yarn build stops with the error itself. The usual causes:

• No connection or a timeout: the build downloads the dependencies from the npm registry. Run the command again once you are online; with Docker, finished steps are cached.
• `Invalid URL`: NEXT_PUBLIC_SITE_URL is not a full address. Write it with https://, such as https://www.your-domain.com.
• No space left on device: free space in Docker Desktop, or check what Docker uses with docker system df.
• It fails at the same step every time: build again without the cache.

docker build --no-cache -t publino-landing .

Without Docker, delete the node_modules and .next folders, then run yarn install and yarn build again.

Yarn says its version is 1.22

This project's package.json defines "packageManager": "yarn@4.6.0…". However the current global version of Yarn is 1.22…

The project pins Yarn 4 through Corepack. This message means Corepack is not enabled yet, so an old global Yarn answered instead.

corepack enable

Then run yarn install again. Use Yarn rather than npm: yarn.lock is what keeps your install on the versions the template was tested with.

The corepack command is not found

corepack: command not found

Node.js 25 and newer no longer include Corepack. Install it once with npm, then turn it on:

npm install -g corepack
corepack enable

Then run yarn install again. The same two commands fix yarn: command not found.

Node.js is too old

You are using Node.js 18.20.4. For Next.js, Node.js version ">=20.9.0" is required.

Next.js 16 needs Node.js 20.9 or newer. Check your version with node -v. Install Node.js 22 or 24, open a new terminal, run corepack enable again, then yarn install and yarn dev.

With Docker this does not apply: the image brings its own Node.js 24.

A changed setting does nothing

NEXT_PUBLIC_SITE_URL and the other NEXT_PUBLIC_ values are compiled into the site when it is built. Changing one changes nothing until the site is built again.

• The settings

yarn start fails, or shows an old version

Could not find a production build in the '.next' directory. Try building your app with 'next build' before starting the production server.

yarn start serves the last production build, from the .next folder. Run yarn build first, and again after every change.

If the site shows errors that do not match your code, often after you changed a dependency's version or BUILD_STANDALONE, delete the .next folder and build again:

rm -rf .next
yarn build

On Windows, in PowerShell, delete it with Remove-Item -Recurse -Force .next.

A form says it was sent, but nothing arrives

That is how the template ships. The contact form and the form on the home page check what visitors type and show their success message, but they send nothing anywhere until you connect each one to your own service.

• The forms

The captcha shows an error

ERROR for site owner: Invalid domain for site key

The home page form shows a Google reCAPTCHA checkbox only when NEXT_PUBLIC_RECAPTCHA_SITE_KEY is set. This message means the domain you opened the site on is not in that key's list of domains. In the reCAPTCHA admin console, add your domain, and localhost to try it on your computer. The key must be a reCAPTCHA v2 "I'm not a robot" key.

To remove the captcha step, leave the variable empty and build again.

• The captcha

A button does nothing

Some buttons are placeholders by design, ready for you to point at your own pages: Login and Book a call in the header, Get Started and Learn More in the hero, Explore Templates in the responsive section, Browse All Templates, and the buttons and menu items inside the dashboard mockup. The social links on the contact page point to #. The header links, the plan buttons and the template cards already work.

• Links and buttons

A template preview image does not show

Invalid src prop (https://…) on `next/image`, hostname "…" is not configured under images in your `next.config.js`

The four sample template cards on the home page load their previews from the Aniq UI image server, which next.config.js allows. Without an internet connection they stay empty. If you point a card at an image on another server, Next.js stops with the message above: put the image in public/ instead, or add its host to images.remotePatterns in next.config.js.

The site opens in Arabic

Opening / sends a visitor to /ar when the browser prefers Arabic. Once a visitor picks a language in the header's menu, the site remembers it. Choose English in the menu, or open /pricing or another page without a prefix.

• Languages

The site stays dark, or stays light

The site opens in the dark theme. The sun and moon button in the header switches it, and the browser remembers the choice. To check what a new visitor sees, clear the site data for localhost:3030 in your browser, or open a private window.

• The themes

The folder looks different

Run the commands inside the folder the ZIP extracts to, Publino-template. It holds Dockerfile, package.json, yarn.lock, messages, public and src. If the unzip command is missing, extract it with your file manager instead; some tools add an extra folder named after the ZIP, so move into the inner one.