# KnowIssues

### UI-O-Matic and Autofac&#x20;

In case you are using Autofac you'll need to registed the UI-O-Matic tree controller

```
builder.RegisterApiControllers(typeof(UIOMatic.Web.Controllers.UIOMaticTreeController).Assembly);
```

You'll get the error

```
"Message": "An error has occurred.",
"ExceptionMessage": "Object reference not set to an instance of an object.",
"ExceptionType": "System.NullReferenceException",
"StackTrace": "   at Umbraco.Web.Trees.ApplicationTreeExtensions.TryLoadFromControllerTree ...
```

### Bugs

For an overview of issues or to report new ones please go to <https://github.com/TimGeyssens/UIOMatic/issues>
