# Troubleshooting

An assortment of troubleshooting tips.

## `wails` 명령어를 찾을 수 없나요?

시스템에서 `wails` 명령어를 찾을 수 없는 경우 Go 설치 지침을 잘 따라했는지 확인해보세요. Normally, it means that the `go/bin` directory in your User's home directory is not in the `PATH` environment variable. You will also normally need to close and reopen any open command prompts so that changes to the environment made by the installer are reflected at the command prompt.

## My application is displaying a white/blank screen

Check that your application includes the assets from the correct directory. In your `main.go` file, you will have something similar to the following code:

```go
//go:embed all:frontend/dist
var assets embed.FS
```

Check that `frontend/dist` contains your application assets.

### Mac

If this happens on Mac, try adding the following to your `Info.plist`:

```xml
<key>NSAppTransportSecurity</key>
<dict>
    <key>NSAllowsLocalNetworking</key>
    <true/>
</dict>
```

Reference: https://github.com/wailsapp/wails/issues/1504#issuecomment-1174317433

## Mac application not valid

If your built application looks like this in finder:

```mdx-code-block
<p className="text--center">
  <img
    src={
      require("@site/static/img/troubleshooting/invalid_mac_app.png").default
    }
  />
</p>
```

it's likely that your application's `info.plist` is invalid. Update the file in `build/<yourapp>.app/Contents/info.plist` and check if the data is valid, EG check the binary name is correct. To persist the changes, copy the file back to the `build/darwin` directory.

## Cannot call backend method from frontend with variadic arguments

If you have a backend method defined with variadic parameters, eg:

```go
func (a *App) TestFunc(msg string, args ...interface{}) error {
    // Code
}
```

calling this method from the frontend like this will fail:

```js
var msg = "Hello: ";
var args = ["Go", "JS"];
window.go.main.App.TestFunc(msg, ...args)
  .then((result) => {
    //do things here
  })
  .catch((error) => {
    //handle error
  });
```

Workaround:

```js
var msg = "Hello ";
var args = ["Go", "JS"];
window.go.main.App.TestFunc(msg, args)
  .then((result) => {
    //without the 3 dots
    //do things here
  })
  .catch((error) => {
    //handle error
  });
```

Credit: https://github.com/wailsapp/wails/issues/1186

## I'm having getting proxy errors when trying to install Wails

If you are getting errors like this:

```
"https://proxy.golang.org/github.com/wailsapp/wails/cmd/wails/@v/list": dial tcp 172.217.163.49:443: connectex: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
```

it's probably because the official Go Proxy is being blocked (Users in China have reported this). The solution is to set up the proxy manually, eg:

```
go env -w GO111MODULE=on
go env -w GOPROXY=https://goproxy.cn,direct
```

Source: https://github.com/wailsapp/wails/issues/1233

## The generated TypeScript doesn't have the correct types

Sometimes the generated TypeScript doesn't have the correct types. To mitigate this, it is possible to specify what types should be generated using the `ts_type` struct tag. For more details, please read [this](https://github.com/tkrajina/typescriptify-golang-structs#custom-types).

## When I navigate away from `index.html`, I am unable to call methods on the frontend

If you navigate away from `index.html` to a new html file, the context will be lost. This can be fixed by adding the following imports to the `<head>` section of any new page you navigate to:

```html
<head>
  <script src="/wails/ipc.js"></script>
  <script src="/wails/runtime.js"></script>
</head>
```

Source: https://github.com/wailsapp/wails/discussions/1512

## I get `too many open files` errors on my Mac when I run `wails dev`

By default, macOS will only allow you to open a maximum of 256 files. This can affect the `wails dev` command. This limit can be increased by running: `ulimit -n 1024` in the terminal.

FSNotify is [looking to move to Apple's fsevents](https://github.com/fsnotify/fsnotify/issues/11) for Mac. If this isn't completed soon, we will create our own implementation, tracked [here](https://github.com/wailsapp/wails/issues/1733).

## My Mac app gives me weird compilation errors

A few users have reported seeing compilation errors such as the following:

```shell
# github.com/wailsapp/wails/v2/internal/frontend/desktop/darwin
In file included from ../../pkg/mod/github.com/wailsapp/wails/v2@v2.0.0-beta.44.2/internal/frontend/desktop/darwin/callbacks.go:9:
In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX12.1.sdk/System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:12:
/Library/Developer/CommandLineTools/SDKs/MacOSX12.1.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSBundle.h:91:143: error: function does not return NSString
- (NSAttributedString *)localizedAttributedStringForKey:(NSString *)key value:(nullable NSString *)value table:(nullable NSString *)tableName NS_FORMAT_ARGUMENT(1) NS_REFINED_FOR_SWIFT API_AVAILABLE(macos(12.0), ios(15.0), watchos(8.0), tvos(15.0));
                                                         ~~~~~~~~~~~~~~                                                                       ^                  ~
/Library/Developer/CommandLineTools/SDKs/MacOSX12.1.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:103:48: note: expanded from macro 'NS_FORMAT_ARGUMENT'
        #define NS_FORMAT_ARGUMENT(A) __attribute__ ((format_arg(A)))
```

This is _normally_ due to a mismatch with the OS version you are running and the version of the XCode Command Line Tools installed. If you see an error like this, try upgrading your XCode Command Line Tools to the latest version.

If reinstalling Xcode Command Tools still fails, you can check the path where the toolkit is located using:

`xcode-select -p`

If `/Applications/Xcode.app/Contents/Developer` is displayed, run `sudo xcode-select --switch /Library/Developer/CommandLineTools`

Sources: https://github.com/wailsapp/wails/issues/1806 and https://github.com/wailsapp/wails/issues/1140#issuecomment-1290446496

--

## Cannot start service: Host version "x.x.x does not match binary version "x.x.x"

It's preferable to add `frontend/node_modules` and `frontend/package-lock.json` to your `.gitignore`. Otherwise when opening your repository on another machine that may have different versions of Node installed, you may not be able to run your application.

If this does happen, simply delete `frontend/node_modules` and `frontend/package-lock.json` and run your `wails build` or `wails dev` command again.

## Build process stuck on "Generating bindings"

Bindings generation process runs your application in a special mode. If application, intentionally or unintentionally, contains an endless loop (i.e. not exiting after `wails.Run()` finished), this can lead to build process stuck on the stage of bindings generation. Please make sure your code exits properly.
