This time issue is that i tried to configure a protection group to protect a folder that is about 16 GB in size. but when i walk through the New Protection Group wizard it says that it requires about 920 GB size (WOW) ,
by reviewing the disk space that hosting the folder i noticed that the used space equals 601.74 GB which is the amount of data DPM wants to protect even i selected the specific folder not the whole drive
Now you can continue with the wizard.
I don’t know if Microsoft solved this in a hot fix or Cumulative update. hope this been helpful for you