Colorsource Offline Editor currently Imports and Exports to and from the lowest drive letter identified by your computer. This only includes drives identified as Removable Storage.
Steps to Solution
Open the File Browser and select "Computer".
Check to see how many "Devices with Removable Storage" are present. The file with Import or Export from the lowest Drive Letter.
Remove all devices that have a lower drive letter than the one you want to Import from or Export to.
Open ColorSource Offline Editor and Import/Export the File.