AbleCommerce Shopping Cart Software

I have been working with AbleCommerce for a couple of weeks now, and I suddenly find that I can no longer get to the checkout page. I have traced the code, and when I click the Checkout button, I get to a point in NavigationHelper.cs where it calls WebflowManager.IsUsingOnePageCheckout(). This function never returns, and the page just repaints. I have tried reverting to the original source code (but have not re-initialized the database), but it still does not work. Does anyone have any ideas as to what might be wrong?

Thanks

I believe I have found the problem. Looking in the log file, I see that an exception was being thrown because the Scriplets\Custom directory did not exist (I guess I must have deleted it). Restoring that directory corrected the problem.