InnerMessage:Object reference not set to an instance of an object.

InnerStackTrace:

at DotNetNuke.Professional.Workflows.View.BindAction(Int32 portalId)
at DotNetNuke.Professional.Workflows.View.OnLoad(EventArgs e)

Cause: 

When upgrading, the workflow for publishing is not set to direct, and upgrading to 8 in this configuration causes this error.

Resolution:

Make sure your workflow is set to direct before upgrading to DNN version 8.  To do this follow these steps:

1. Click Edit Settings for the problematic HTML module prior to upgrade
2. Click the "HTML Module Settings" tab
3. Verify that the Workflow row's drop-down box is set to Direct Publish.