Lynn,

>In my application I have a WPF user interface. I have been unable to successfully register a mm.net business object in the code behind file. So I created some "controller" classes and tried to register the bussiness objects there.
>
>In the XAML code behind file, I would get an error at run time: "Object reference not set to an instance of an object." as soon as the RegisterBizObject command was executed.
>In the controller class, the error didn't occur until I tried to query data using a method contained in the registered object.
>
>Does anyone have some good information on the RegisterBizObject command:
> Where it can and cannot be used?
> What needs to be done before this command is run?
> Is it possible to register a business object in a class that is not associated with a control?
>
>Any ideas or help would be greatly appreciated.
>
>Lynn 8-)

When you call a method on the business object there are lots of other objects that get created. Most likely it will have something to do with the DataAccessClasses that are not getting created for some reason. You indicated the error didn't occur until you tried to call a method on the registerd business object, so registering it wasn't likely the problem. If you can post the full stack trace it might be easier to see which object isn't getting created. Alternatively, you could set a breakpoint in the method you are calling and step into the MM code to find out what is happening.
Tim