> For the complete documentation index, see [llms.txt](https://vitrina-blogerov.gitbook.io/bloggers-showcase/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://vitrina-blogerov.gitbook.io/bloggers-showcase/product-docs/product-docs-en/architecture/error-pages.md).
# Error pages
Error pages are shown when the user lands on a protected route, a non-existent page, or when the backend is temporarily unavailable.
{% hint style="info" %}
The platform has two levels of errors: edge errors from Caddy and backend errors from FastAPI. These are different situations.
{% endhint %}
### Which errors are used
| Code | When it appears |
| ----- | ------------------------------------------------ |
| `403` | Access denied. |
| `404` | Page or path not found. |
| `502` | Caddy could not get a response from the backend. |
### Where the pages are located
{% tabs %}
{% tab title="Edge Caddy" %}
```
/opt/bloggers_platform/edge/www/errors/403.html
/opt/bloggers_platform/edge/www/errors/404.html
/opt/bloggers_platform/edge/www/errors/502.html
```
These pages are shown by Caddy.
{% endtab %}
{% tab title="Backend" %}
```
templates/403.html
templates/404.html
templates/502.html
```
These pages are located inside the language version and can be used by the backend layer.
{% endtab %}
{% endtabs %}
### How the page is chosen
```mermaid
flowchart TB
A["User request"] --> B{"Did Caddy find the route?"}
B -->|no| C["Edge 404"]
B -->|yes| D{"Does the backend respond?"}
D -->|no| E["Edge 502"]
D -->|yes| F["FastAPI"]
F --> G{"Is access available?"}
G -->|no| H["403"]
G -->|yes| I["Page or API response"]
```
### Important
If a white screen appears on a non-existent path
Most often this means the error page loaded, but failed to pull in styles or the background. You need to check the absolute paths to `/assets/style.css` and `/assets/bg.mp4`.
If the standard Caddy error is visible
It means Caddy could not find or could not serve the branded page from `/errors`. Check the folder `/opt/bloggers_platform/edge/www/errors`.
If 502 appears
Check the backend container for the required language version and the shared edge:
```bash
sudo /opt/bloggers_platform/apps/ru/manager.sh status
sudo /opt/bloggers_platform/manager.sh status
```
---
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