An upgrade does not "add the features" to your existing Vue 4 program, it allows you to purchase the full Vue 5 if you have Vue 4 already at a reduced cost, it will simply ask you to prove you have Vue 4 on your system and then install Vue 5, The program does not become a hybrid Vue 4&5 program, it becomes Vue 5, no difference from the Full version in features or functionality. Also, Just FYI, Vue 5 will not read Vue 2 or 3 files, you must use the conversion utility that comes with the Vue 5 software (like Vue 4 Pro and in the future Vue 5 Pro).