When i say that Digital File Pro is no longer supported, i mean that it would not have been updated for compatibility with DWCS5, so if that is the Dreamweaver version you are using, that is likely the cause of the problem, that is why i asked about the Dreamweaver version.
Digital File Pro was integrated into Universal Email 4, Universal Email 4 was then integrated into CSS From Builder 2
since you own DFP, you would qualify for upgrade pricing (50% off) on UE4, but since you own CSS Form Builder 1, you also qualify for upgrade pricing to CSS From builder 2 (50% off) which include the functionality of both DFP and Universal Email.
If you contact the sales department, I'm sure they will give all the details on possible upgrade paths.