Install the newest codemeter software (help found here http://support.codemeter.de/en/index.html ) Download the update files from esim and install them...activate the updated licence and that is pretty much it.
No need to purchase, download or install older versions.
I know of no specific case where they did not. Of course, it depends on how old they really are. For example, in old SB1 scenarios it is possible to drive across water bodies that aren't very wide - these routes would eventually require some editing. But this is the most extreme case that I can remember, and I suppose that most old scenarios have been updated over the past six years.