Current Chrysler software version is V7.54 , what version are you running? Did you check Function Viewer and see if it shows immobilizer key programming for your model?. Are you at where all the  keys were lost? It might only offer the ability to add additional keys to be programmed  providing you started off with  one that is programmed which starts the vehicle.  

 Strange that Function Viewer for Dodge and Chrysler for Town & Country/ Caravan/ Voyager are only displayed for 2007-2017 Models, so kinda have to figure I should have kept my old DS708 , because I have to assume some older model  coverage functions must have taken a hit for legal reasons and licensing fee budget cuts, that they are  unable to maintain as in depth older model coverage, if the  function viewer no longer displays the available functions for older the models older than  2007. All the more reason to not buy a new year of updates, keep scanner with old coverage,  and just replace the platform a few years later. My guess is if the update doesn't say added function or coverage , and it is Software optimization ?, is it is possibly fixing some glitches and errors, but at same time maybe something has to be pulled or disabled to be in court compliance or avoid court by removing something in contention with an OE manufacturer