It should give you something like this, so a summary of what you have done and what work is left. The table is also configurable so you can change this report to show the work left based on what you do and your workflow:
On your error... this is the first error I have seen with this report so I don't really know what to suggest! The message you got has sometime been filetype related in the past and was resolved with the new Word filetype, but I don't know if this is linked at all. I suggest you log this with support through your support contract so they can investigate why, especially if you think this sort of report is what you're looking for.