# AUR0009

### **Error message**

Attempted to jitRegister something that is not a constructor: '`yyyy`'. Did you forget to register this resource?

### **Parameters**

key (any)

### Error explanation

This error occurs when the DI container tries to automatically register (jitRegister) a value that is not a constructor (class or function) or a registry. The container cannot instantiate or resolve such a value, so it throws this error.

### Common causes

* Attempting to resolve a key that is not a class, function, or registry.
* Typo or incorrect value passed to `container.get()` or dependency injection.
* The resource was not registered before being resolved.
* A plugin or library is trying to resolve an unregistered or invalid key.

### How to fix

* Register the key with the container before attempting to resolve it.
* Ensure the key you are resolving is a valid constructor, function, or registry.
* Double-check for typos or incorrect values in your registration and resolution code.
* If using plugins, ensure they are properly configured and registered.

### Debugging tips

* Check the stack trace to see where the resolution was attempted.
* Search your codebase for all registrations and resolutions of the key in question.
* If using plugins, try disabling them one at a time to isolate the source.