"An unexpected error has occurred" when viewing a SharePoint task

I was getting the following message when some users were logging in to close their tasks:

An unexpected error has occurred.

The correlation ID associated to this error in the ULS logs was the following:

System.ArgumentNullException: Value cannot be null.  Parameter name: item    at Microsoft.Office.Workflow.ListPage.SimpleNameFromItem(SPListItem item)

Turns out in our environment we have users logging in from multiple domains, and the account trying to view the task didn't have access to the associated item to the task.  After giving that item permissions to the proper account, all was well.