feat(docs): add a desktop troubleshooting guide (#10397)

packages/web/src/content/docs/troubleshooting.mdx

@@ -3,17 +3,16 @@ title: Troubleshooting
 description: Common issues and how to resolve them.
 ---
 
-To debug any issues with OpenCode, you can check the logs or the session data
-that it stores locally.
+To debug issues with OpenCode, start by checking the logs and local data it stores on disk.
 
 ---
 
-### Logs
+## Logs
 
 Log files are written to:
 
 - **macOS/Linux**: `~/.local/share/opencode/log/`
-- **Windows**: `%USERPROFILE%\.local\share\opencode\log\`
+- **Windows**: Press `WIN+R` and paste `%USERPROFILE%\.local\share\opencode\log`
 
 Log files are named with timestamps (e.g., `2025-01-09T123456.log`) and the most recent 10 log files are kept.
 
@@ -21,12 +20,12 @@ You can set the log level with the `--log-level` command-line option to get more
 
 ---
 
-### Storage
+## Storage
 
 opencode stores session data and other application data on disk at:
 
 - **macOS/Linux**: `~/.local/share/opencode/`
-- **Windows**: `%USERPROFILE%\.local\share\opencode`
+- **Windows**: Press `WIN+R` and paste `%USERPROFILE%\.local\share\opencode`
 
 This directory contains:
 
@@ -38,6 +37,132 @@ This directory contains:
 
 ---
 
+## Desktop app
+
+OpenCode Desktop runs a local OpenCode server (the `opencode-cli` sidecar) in the background. Most issues are caused by a misbehaving plugin, a corrupted cache, or a bad server setting.
+
+### Quick checks
+
+- Fully quit and relaunch the app.
+- If the app shows an error screen, click **Restart** and copy the error details.
+- macOS only: `OpenCode` menu -> **Reload Webview** (helps if the UI is blank/frozen).
+
+---
+
+### Disable plugins
+
+If the desktop app is crashing on launch, hanging, or behaving strangely, start by disabling plugins.
+
+#### Check the global config
+
+Open your global config file and look for a `plugin` key.
+
+- **macOS/Linux**: `~/.config/opencode/opencode.jsonc` (or `~/.config/opencode/opencode.json`)
+- **macOS/Linux** (older installs): `~/.local/share/opencode/opencode.jsonc`
+- **Windows**: Press `WIN+R` and paste `%USERPROFILE%\.config\opencode\opencode.jsonc`
+
+If you have plugins configured, temporarily disable them by removing the key or setting it to an empty array:
+
+```jsonc
+{
+  "$schema": "https://opencode.ai/config.json",
+  "plugin": [],
+}
+```
+
+#### Check plugin directories
+
+OpenCode can also load local plugins from disk. Temporarily move these out of the way (or rename the folder) and restart the desktop app:
+
+- **Global plugins**
+  - **macOS/Linux**: `~/.config/opencode/plugins/`
+  - **Windows**: Press `WIN+R` and paste `%USERPROFILE%\.config\opencode\plugins`
+- **Project plugins** (only if you use per-project config)
+  - `<your-project>/.opencode/plugins/`
+
+If the app starts working again, re-enable plugins one at a time to find which one is causing the issue.
+
+---
+
+### Clear the cache
+
+If disabling plugins doesn't help (or a plugin install is stuck), clear the cache so OpenCode can rebuild it.
+
+1. Quit OpenCode Desktop completely.
+2. Delete the cache directory:
+
+- **macOS**: Finder -> `Cmd+Shift+G` -> paste `~/.cache/opencode`
+- **Linux**: delete `~/.cache/opencode` (or run `rm -rf ~/.cache/opencode`)
+- **Windows**: Press `WIN+R` and paste `%USERPROFILE%\.cache\opencode`
+
+3. Restart OpenCode Desktop.
+
+---
+
+### Fix server connection issues
+
+OpenCode Desktop can either start its own local server (default) or connect to a server URL you configured.
+
+If you see a **"Connection Failed"** dialog (or the app never gets past the splash screen), check for a custom server URL.
+
+#### Clear the desktop default server URL
+
+From the Home screen, click the server name (with the status dot) to open the Server picker. In the **Default server** section, click **Clear**.
+
+#### Remove `server.port` / `server.hostname` from your config
+
+If your `opencode.json(c)` contains a `server` section, temporarily remove it and restart the desktop app.
+
+#### Check environment variables
+
+If you have `OPENCODE_PORT` set in your environment, the desktop app will try to use that port for the local server.
+
+- Unset `OPENCODE_PORT` (or pick a free port) and restart.
+
+---
+
+### Linux: Wayland / X11 issues
+
+On Linux, some Wayland setups can cause blank windows or compositor errors.
+
+- If you're on Wayland and the app is blank/crashing, try launching with `OC_ALLOW_WAYLAND=1`.
+- If that makes things worse, remove it and try launching under an X11 session instead.
+
+---
+
+### Windows: WebView2 runtime
+
+On Windows, OpenCode Desktop requires the Microsoft Edge **WebView2 Runtime**. If the app opens to a blank window or won't start, install/update WebView2 and try again.
+
+---
+
+### Notifications not showing
+
+OpenCode Desktop only shows system notifications when:
+
+- notifications are enabled for OpenCode in your OS settings, and
+- the app window is not focused.
+
+---
+
+### Reset desktop app storage (last resort)
+
+If the app won't start and you can't clear settings from inside the UI, reset the desktop app's saved state.
+
+1. Quit OpenCode Desktop.
+2. Find and delete these files (they live in the OpenCode Desktop app data directory):
+
+- `opencode.settings.dat` (desktop default server URL)
+- `opencode.global.dat` and `opencode.workspace.*.dat` (UI state like recent servers/projects)
+
+To find the directory quickly:
+
+- **macOS**: Finder -> `Cmd+Shift+G` -> `~/Library/Application Support` (then search for the filenames above)
+- **Linux**: search under `~/.local/share` for the filenames above
+- **Windows**: Press `WIN+R` -> `%APPDATA%` (then search for the filenames above)
+
+---
+
 ## Getting help
 
 If you're experiencing issues with OpenCode:
@@ -113,6 +238,8 @@ To resolve this:
    rm -rf ~/.local/share/opencode
    ```
 
+   On Windows, press `WIN+R` and delete: `%USERPROFILE%\.local\share\opencode`
+
 3. Re-authenticate with your provider using the `/connect` command in the TUI.
 
 ---
@@ -129,6 +256,8 @@ To resolve provider package issues:
    rm -rf ~/.cache/opencode
    ```
 
+   On Windows, press `WIN+R` and delete: `%USERPROFILE%\.cache\opencode`
+
 2. Restart opencode to reinstall the latest provider packages
 
 This will force opencode to download the most recent versions of provider packages, which often resolves compatibility issues with model parameters and API changes.