You need to specify an existing version folder if one or more files inside a SmartVersion File are not actually stored inside the SmartVersion File with their data, but just size, date, and checksum information. Such files correspond to a Minimal Patch.
This may happen both when adding new versions to a SmartVersion file and extracting versions from a SmartVersion file. To specify an existing version folder:
Open the SmartVersion File that needs to have an existing version folder specified.
Click Version, then click Specify base directory of a version.
In the Browse for Folder dialog, choose the directory that contains the existing version.