APM

>Agent Skill

@microsoft/winapp-troubleshoot

skilldevelopment

Diagnose and fix common Windows app packaging, signing, identity, and SDK errors. Use when encountering errors with MSIX packaging, certificate signing, Windows SDK setup, or app installation.

development
apm::install
$apm install @microsoft/winapp-troubleshoot
apm::skill.md
---
name: winapp-troubleshoot
description: Diagnose and fix common Windows app packaging, signing, identity, and SDK errors. Use when encountering errors with MSIX packaging, certificate signing, Windows SDK setup, or app installation.
version: 0.2.1
---
## When to use

Use this skill when:
- **Diagnosing errors** from winapp CLI commands
- **Choosing the right command** for a task
- **Understanding prerequisites** — what each command needs and what it produces

## Common errors & solutions

| Error | Cause | Solution |
|-------|-------|----------|
| "winapp.yaml not found" | Running `restore` or `update` without config | Run `winapp init` first, or `cd` to the directory containing `winapp.yaml` |
| "appxmanifest.xml not found" | Running `package`, `create-debug-identity`, or `cert generate --manifest` | Run `winapp init` or `winapp manifest generate` first, or pass `--manifest <path>` |
| "Publisher mismatch" | Certificate publisher ≠ manifest publisher | Regenerate cert: `winapp cert generate --manifest`, or edit `appxmanifest.xml` `Identity.Publisher` to match |
| "Access denied" / "elevation required" | `cert install` without admin | Run terminal as Administrator for `winapp cert install` |
| "Package installation failed" | Cert not trusted, or stale package registration | `winapp cert install ./devcert.pfx` (admin), then `Get-AppxPackage <name> \| Remove-AppxPackage` |
| "Certificate not trusted" | Dev cert not installed on machine | `winapp cert install ./devcert.pfx` (admin) |
| "Build tools not found" | First run, tools not yet downloaded | Run `winapp update` to download tools; ensure internet access |
| "Failed to add package identity" | Stale debug identity or untrusted cert | `Get-AppxPackage *yourapp* \| Remove-AppxPackage` to clean up, then `winapp cert install` and retry |
| "Certificate file already exists" | `devcert.pfx` already present | Use `winapp cert generate --if-exists overwrite` or `--if-exists skip` |
| "Manifest already exists" | `appxmanifest.xml` already present | Use `winapp manifest generate --if-exists overwrite` or edit manifest directly |

## Command selection guide

```
Does the project have an appxmanifest.xml?
├─ No → Do you want full setup (manifest + config + optional SDKs)?
│       ├─ Yes → winapp init (adds Windows platform files to existing project)
│       └─ No, just a manifest → winapp manifest generate
└─ Yes
   ├─ Has winapp.yaml, cloned/pulled but .winapp/ folder missing?
   │  └─ winapp restore
   ├─ Want newer SDK versions?
   │  └─ winapp update
   ├─ Need a dev certificate?
   │  └─ winapp cert generate (then winapp cert install for trust)
   ├─ Need package identity for debugging?
   │  └─ winapp create-debug-identity <exe>
   ├─ Ready to create MSIX installer?
   │  └─ winapp package <build-output> --cert ./devcert.pfx
   ├─ Need to sign an existing file?
   │  └─ winapp sign <file> <cert>
   ├─ Need to update app icons?
   │  └─ winapp manifest update-assets ./logo.png
   ├─ Need to run SDK tools directly?
   │  └─ winapp tool <toolname> <args>
   ├─ Need to publish to Microsoft Store?
   │  └─ winapp store <args> (passthrough to Store Developer CLI)
   └─ Need the .winapp directory path for build scripts?
      └─ winapp get-winapp-path (or --global for shared cache)
```

**Important notes:**
- `winapp init` adds files to an **existing** project — it does not create a new project
- The key prerequisite for most commands is `appxmanifest.xml`, not `winapp.yaml`
- `winapp.yaml` is only needed for SDK version management (`restore`/`update`)
- Projects with NuGet package references (e.g., `.csproj` referencing `Microsoft.Windows.SDK.BuildTools`) can use winapp commands without `winapp.yaml`
- For Electron projects, use the npm package (`npm install --save-dev @microsoft/winappcli`) which includes Node.js-specific commands under `npx winapp node`

## Prerequisites & state matrix

| Command | Requires | Creates/Modifies |
|---------|----------|------------------|
| `init` | Existing project (any framework) | `winapp.yaml`, `.winapp/`, `appxmanifest.xml`, `Assets/`, `.gitignore` update |
| `restore` | `winapp.yaml` | `.winapp/packages/`, generated projections |
| `update` | `winapp.yaml` | Updates versions in `winapp.yaml`, reinstalls packages |
| `manifest generate` | Nothing | `appxmanifest.xml`, `Assets/` |
| `manifest update-assets` | `appxmanifest.xml` + source image | Regenerates `Assets/` icons |
| `cert generate` | Nothing (or `appxmanifest.xml` for publisher) | `devcert.pfx` |
| `cert install` | Certificate file + admin | Machine certificate store |
| `create-debug-identity` | `appxmanifest.xml` + exe + trusted cert | Registers sparse package with Windows |
| `package` | Build output + `appxmanifest.xml` | `.msix` file |
| `sign` | File + certificate | Signed file (in-place) |
| `create-external-catalog` | Directory with executables | `CodeIntegrityExternal.cat` |
| `tool <name>` | Nothing (auto-downloads tools) | Runs SDK tool directly |
| `store` | Nothing (auto-downloads Store CLI) | Passthrough to Microsoft Store Developer CLI |
| `get-winapp-path` | Nothing | Prints `.winapp` directory path |

## Debugging tips

- Add `--verbose` (or `-v`) to any command for detailed output
- Add `--quiet` (or `-q`) to suppress progress messages (useful in CI/CD)
- Run `winapp --cli-schema` to get the full JSON schema of all commands and options
- Run any command with `--help` for its specific usage information
- Use `winapp get-winapp-path` to find where packages are stored locally
- Use `winapp get-winapp-path --global` to find the shared cache location

## Getting more help

- Full CLI documentation: https://github.com/microsoft/WinAppCli/blob/main/docs/usage.md
- Framework-specific guides: https://github.com/microsoft/WinAppCli/tree/main/docs/guides
- File an issue: https://github.com/microsoft/WinAppCli/issues

## Related skills
- **Setup & init**: `winapp-setup` — adding Windows support to a project
- **Manifest**: `winapp-manifest` — creating and editing `appxmanifest.xml`
- **Signing**: `winapp-signing` — certificate generation and management
- **Packaging**: `winapp-package` — creating MSIX installers
- **Identity**: `winapp-identity` — enabling package identity for Windows APIs
- **Frameworks**: `winapp-frameworks` — framework-specific guidance (Electron, .NET, C++, Rust, Flutter, Tauri)


## Command Reference

### `winapp get-winapp-path`

Print the path to the .winapp directory. Use --global for the shared cache location, or omit for the project-local .winapp folder. Useful for build scripts that need to reference installed packages.

#### Options
<!-- auto-generated from cli-schema.json -->
| Option | Description | Default |
|--------|-------------|---------|
| `--global` | Get the global .winapp directory instead of local | (none) |

### `winapp tool`

Run Windows SDK tools directly (makeappx, signtool, makepri, etc.). Auto-downloads Build Tools if needed. For most tasks, prefer higher-level commands like 'package' or 'sign'. Example: winapp tool makeappx pack /d ./folder /p ./out.msix

**Aliases:** `run-buildtool`

### `winapp store`

Run a Microsoft Store Developer CLI command. This command will download the Microsoft Store Developer CLI if not already downloaded. Learn more about the Microsoft Store Developer CLI here: https://aka.ms/msstoredevcli