Getting started: add troubleshooting page (#33947)

* Getting started: add troubleshooting page

- on onboarding/ installation issues
- partially addresses feedback from #33838

* Fix URLs

* Remove refs to issue report steps

* Update source/getting-started/troubleshooting.markdown

Co-authored-by: Stefan Agner <stefan@agner.ch>

* Update source/getting-started/troubleshooting.markdown

Co-authored-by: Stefan Agner <stefan@agner.ch>

* Fix step numbers

* Fix typo

* Add steps about stuck at 'preparing'

* Move troubleshooting in TOC

* Update source/getting-started/troubleshooting.markdown

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

* Move troubleshooting in TOC

* Fix links

* Reorder steps to start checks with physical layer

* Fix TOC entry

* Add refresh icon

* reword

* Fix  TOC

* list specific pages HA needs access to during installation/setup

* Remove 2nd symptom. it is covered by remedy of symtom 1

* Remove redundant step

* Fix link behavior

* Fix typo

* Update source/installation/troubleshooting.markdown

Co-authored-by: Stefan Agner <stefan@agner.ch>

* clarify network step

* Add step about allowing NTP

* Update source/installation/troubleshooting.markdown

Co-authored-by: Stefan Agner <stefan@agner.ch>

* Simplify sentence

* Update source/installation/troubleshooting.markdown

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

* Update source/installation/troubleshooting.markdown

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

* Update source/installation/troubleshooting.markdown

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

* Update source/installation/troubleshooting.markdown

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

---------

Co-authored-by: Stefan Agner <stefan@agner.ch>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

source/_docs/troubleshooting.markdown

@@ -1,7 +0,0 @@
----
-title: "Troubleshooting installation problems"
-description: "Common installation problems and their solutions."
----
-
-It can happen that you run into trouble while installing Home Assistant. This page is here to help you solve the most common problems.
-

source/_includes/asides/getting_started_navigation.html

@@ -18,6 +18,7 @@
           <li>{% active_link /installation/macos macOS %}</li>
           <li>{% active_link /installation/windows Windows %}</li>
           <li>{% active_link /installation/alternative Other systems %}</li>
+          <li>{% active_link /installation/troubleshooting/ Troubleshooting %}</li>
         </ul>
         {% endif %}
       </li>

source/_redirects

@@ -347,8 +347,6 @@ layout: null
 /getting-started/scripts-service-calls /docs/scripts/service-calls
 /getting-started/scripts-conditions /docs/scripts/conditions
 /getting-started/securing /docs/configuration/securing
-/getting-started/troubleshooting /docs/troubleshooting
-/getting-started/troubleshooting-configuration /docs/troubleshooting
 /getting-started/updating /common-tasks/os
 /getting-started/yaml /docs/configuration/yaml
 /getting-started/z-wave /integrations/zwave_js

source/installation/troubleshooting.markdown

@@ -0,0 +1,59 @@
+---
+title: "Troubleshooting installation problems"
+description: "Common installation problems and their solutions."
+---
+
+It can happen that you run into trouble while installing and onboarding Home Assistant. This page is here to help you solve the most common problems.
+
+## Can’t access Home Assistant in my browser
+
+### Symptom: “This site can’t be reached”
+
+When trying to access Home Assistant in the browser, the browser shows the message “This site can’t be reached”.
+
+### Description
+
+This means the browser can’t find your Home Assistant installation on the network.
+
+### Resolution
+
+To resolve this issue, try the following steps:
+
+1. Make sure your Home Assistant device is powered up (LEDs are on).
+2. Make sure your Home Assistant installation is connected to the internet:
+   - Make sure the Ethernet cable is plugged-in to both Home Assistant and to your router or switch.
+   - Make sure your network has internet access.
+     - During first startup, time will be synchronized. Ensure NTP is allowed in your network.
+     - During first startup, Home Assistant completes the installation. It needs access to the following URLs:
+       - version.home-assistant.io: to fetch new version information.
+       - github.com: to update metadata of the add-on store.
+       - ghcr.io: the GitHub container registry to fetch new Home Assistant updates.
+3. Make sure the system on which you opened the browser to access Home Assistant is connected to the same network as Home Assistant.
+   - For example, if the system your Browser runs on is using Wi-Fi, make sure it is using the same Wi-Fi Home Assistant is connected to.
+4. Make sure you typed the address correctly.
+   - Especially if the message includes the error code “ERR_CONNECTION_REFUSED”, it is likely that there was a typo in the port part of the URL (`:8123`).
+   - Typically, the URL is [http://homeassistant.local:8123](http://homeassistant.local:8123).
+   - If you are running an older Windows version or have a stricter network configuration, try [http://homeassistant:8123](http://homeassistant:8123) instead.
+5. The system might still be starting up. Wait for a couple of minutes and refresh the page.
+   - Refreshing might work differently depending on your browser. Look for the refresh {% icon "mdi:refresh" %} icon, or press CTRL+R or CTRL+SHIFT+R.
+6. Check your router's web interface to see what IP address is assigned to your Home Assistant installation.
+   - Enter this IP address (`http://x.x.x.x:8123`) directly into your browser.
+7. If you still can’t reach Home Assistant, connect keyboard and monitor to the device Home Assistant is running on to access the console and see where Home Assistant gets stuck.
+   - If you are using a Home Assistant Green, follow these steps [to access the console](https://green.home-assistant.io/guides/use-terminal/).
+   - If you are using a Home Assistant Yellow, follow these steps [to access the console from Windows](https://yellow.home-assistant.io/guides/use-serial-console-windows/), or [to access the console from Linux or macOS](https://yellow.home-assistant.io/guides/use-serial-console-linux-macos/).
+8. [Reach out to our community for help](https://www.home-assistant.io/help/).
+
+## Stuck at "Preparing Home Assistant"
+
+### Symptom: Onboarding seems stuck at "Preparing Home Assistant"
+
+You are in the onboarding procedure, but the process seems stuck at the step **Preparing Home Assistant**.
+You are seeing this screenshot:
+
+![Home Assistant preparation](/images/getting-started/onboarding_preparing_01.png)
+
+### Resolution
+
+1. Select the pulsing blue dot to view the log files.
+   - The log files might provide more information on the current status.
+2. [Reach out to our community for help](https://www.home-assistant.io/help/).