A few of the imported Desire2Learn courses I have been working with have had Grade Items associated with Dropbox folders that have a negative point value. This was noticed because the Dropbox items are not editable in the Content Tool’s Table of Contents or the Content Viewer. When changes are made in those two areas a message is displayed that the system was unable to make the changes. If you go to the Dropbox folder itself, however, the message that is displayed when you try to edit the item is that it has an invalid value for the number of points possible.
To fix the problem, the value on the Dropbox needs to be changed to a valid entry, and the point value on the Grade Item must be updated as well to a valid entry. After that has been done the item can now be edited.
It might be a good idea to take a look in your managed grades area for any invalid point values associated with any of the Grade Items. Keep in mind that the point values have to be changed on both the Dropbox and the Grade Item. This behavior has not been seen in Discussion Topic or Quizzes of and of the imported courses.