Here is a demonstration video that goes through this process (Set DeviceEditor properties.mov, right click this link to save the movie to disk for better viewing):
Clicking on the "Properties" button at the top left of the DeviceEditor display will pop-up a dialog box that allows you to control some of the aspects of how the session will behave.
By default, DeviceEditor applies an implementation-specific rule and warning message that facilitates the anticipated downstream use of j5 to design the corresponding DNA assembly strategies.
Currently, j5 only allows parts in the first target part bin (equivalent to the leftmost DeviceEditor collection column) to have "Digest" assembly strategies (see the "Target part order list file" page in the j5 user's manual for more information). When placed in other bins, parts with forced "Digest" assembly strategies result in j5 error messages.
To pre-empt these errors, the "Enable digest rule" property, when checked (the default), does not allow parts with a "Digest" forced assembly strategy to be placed into any column except the first column in the collection (if you attempt to do so, DeviceEditor will move the part out of the collection and place it in the part holding area below). When the "Enable digest rule" property is unchecked, parts with a "Digest" forced assembly strategy may be placed into any column.