Add troubleshooting for file uploads (#165)

* Add troubleshooting for file uploads

* add link for file permissions fix

* fix some wording

* fix wording part 2

Author: Boy132

docs/troubleshooting.mdx

@@ -16,7 +16,22 @@ If you see a `500 | SERVER ERROR` or `An unexpected error was encountered while
 tail -n 1000 /var/www/pelican/storage/logs/laravel-$(date +%F).log | grep "\[$(date +%Y)"
 ```
 
-If the command above doesn't return anything you most likely have wrong permissions for your `storage` folder. So you first need to fix that.  
+<details>
+    <summary>Common errors</summary>
+
+    * `ErrorException: file_put_contents(_____): failed to open stream: Permission denied`: Wrong file permissions/ ownership for the panel files, see [below](#wrong-file-permissions).
+    * `502 Bad Gateway Error`: Make sure that php-fpm is running and that you are using the correct php version in your webserver config.
+    * `CSRF token mismatch`: Enable SSL for your Panel with HTTPS protocol scheme in the `APP_URL`, or set `SESSION_SECURE_COOKIE` to `false` in your `.env` file.
+    * `Connection refused [tcp://_______:6379]`: Redis isn't running or isn't reachable for some other reason. (start by checking the status of the redis service: `systemctl status redis-server`)
+    * `SSL: no alternative certificate subject name matches target host name '_______'`: The used SSL certificate for your panel isn't valid for your panel domain, see [this guide](./guides/ssl) for creating a new SSL certificate.
+    * `General error: 8 attempt to write a readonly database`: Your `database.sqlite` has wrong file permissions and is read-only. Make sure the file is writable and owned by the correct user.
+    * `Class '_____' not found`: This usually means you are missing php extensions. Make sure [all needed extensions](./panel/getting-started#dependencies) are installed and that you are using the correct php version.
+    * `Connection timed out after 5001 milliseconds for _______:8080`: Your panel can't reach wings, see the wings connection issues steps below.
+</details>
+
+### Wrong file permissions
+
+If the command above doesn't return anything, you most likely have incorrect file permissions . So you first need to fix that.  
 You can set the correct permissions by running `sudo chmod -R 755 /var/www/pelican/storage/* /var/www/pelican/bootstrap/cache/`. Also make sure that your panel files are owned by the correct user.
 
 <Tabs groupId="webserver">
@@ -37,19 +52,6 @@ You can set the correct permissions by running `sudo chmod -R 755 /var/www/pelic
     </TabItem>
 </Tabs>
 
-<details>
-    <summary>Common errors</summary>
-
-    * `ErrorException: file_put_contents(_____): failed to open stream: Permission denied`: Wrong file permissions/ ownership for the panel files, see above.
-    * `502 Bad Gateway Error`: Make sure that php-fpm is running and that you are using the correct php version in your webserver config.
-    * `CSRF token mismatch`: Enable SSL for your Panel with HTTPS protocol scheme in the APP_URL, or set `SESSION_SECURE_COOKIE` to `false` in your `.env` file.
-    * `Connection refused [tcp://_______:6379]`: Redis isn't running or isn't reachable for some other reason. (start by checking the status of the redis service: `systemctl status redis-server`)
-    * `SSL: no alternative certificate subject name matches target host name '_______'`: The used SSL certificate for your panel isn't valid for your panel domain, see [this guide](./guides/ssl) for creating a new SSL certificate.
-    * `General error: 8 attempt to write a readonly database`: Your `database.sqlite` has wrong file permissions and is readonly. Make sure the file is writeable and owned by the correct user.
-    * `Class '_____' not found`: This usually means you are missing php extensions. Make sure [all needed extensions](./panel/getting-started#dependencies) are installed and that you are using the correct php version.
-    * `Connection timed out after 5001 miliseconds for _______:8080`: Your panel can't reach wings, see the wings connection issues steps below.
-</details>
-
 ## Wings connection issues
 
 ### Check the wings service
@@ -131,3 +133,12 @@ tail -n 100 /var/www/pelican/storage/logs/laravel-$(date +%F).log | grep "\[$(da
 ```
 
 To recreate the queue worker service you can run `php /var/www/pelican/artisan p:environment:queue-service --overwrite`.
+
+## File Upload issues
+
+If a file upload form returns an error like `mountedActionsData.0.files.24d4b82d-a3ae-47fd-981f-8b2f0f6a21d4` it is most likely a proxy issue.
+
+Make sure your `Trusted Proxies` are set to the correct ips, both in the panel settings and your proxy settings!  
+Also make sure your webserver and/ or proxy have a high enough upload limit. (e.g. `client_max_body_size`, `upload_max_filesize` and `post_max_size`)
+
+In some cases the issue can also be caused by incorrect file permissions. See [above](#wrong-file-permissions) on how to fix your file permissions.