Thanks for your reply Eugene -
I am using the explorer that comes with the SUM tool to open the package. I can open all other packages I created, except this package. The package IS password protected, and I do know the password. usually when I open the pacakge with the provided tool, it asks me for the password, and when I put it in, I can see and extract individual files from the .ump package. In this one case, I am getting the provided error message. I tried opening it with WinZip9, but could only see one folder and there were no files within. I will try again on Monday
Aaron