# AUR0022

### **Error message**

The @inject decorator on the target ('xxxx') type 'yyyy' is not supported.

### **Parameters**

* Target name (string)
* Target type (string)

### Error explanation

This error occurs when the `@inject` decorator is used in a way that is not supported by Aurelia's DI system. For example, applying `@inject` to a field, method, or other unsupported target will trigger this error. The `@inject` decorator is intended for use on classes and, in some cases, constructor parameters.

### Common causes

* Using `@inject` on a field, method, or property instead of a class or constructor parameter.
* Incorrect usage of the decorator in TypeScript or JavaScript code.
* Attempting to use `@inject` in a context not supported by Aurelia's DI system.

### How to fix

* Only use `@inject` on classes or constructor parameters.
* Review the documentation for correct usage of the `@inject` decorator.
* Refactor your code to move dependency injection to supported locations (class or constructor).

### Debugging tips

* Check the stack trace to see where the invalid `@inject` usage occurred.
* Search your codebase for all usages of `@inject` and verify they are on classes or constructors.
* If using plugins, try disabling them one at a time to isolate the source.