Role Provider throws Exception has been thrown by the target of an invocation.

I have created a custom role provider. This works great on the development machine. When I deploy it to the production server, I receive the following error message:
Exception has been thrown by the target of an invocation.
When I look in the event viewer, I find the related warning below. What does this mean, and why is it happening?







Event Type:    Warning
Event Source:    ASP.NET 2.0.50727.0
Event Category:    Web Event
Event ID:    1310
Date:        7/16/2009
Time:        1:48:20 PM
User:        N/A
Computer:    *******
Description:
Event code: 3008
Event message: A configuration error has occurred.
Event time: 7/16/2009 1:48:20 PM
Event time (UTC): 7/16/2009 12:48:20 PM
Event ID: a7724f ...