Reallusion provide a download link for the last version of the software that you have purchased in your user account, with the following restrictions:
*NOTE:
We only provide the latest three version re-download service. If you do not see a "Download" link, the re-download period for your purchase has expired.
This means that if you purchase a software with version 3 then as soon as version 7 of this item is released, and you have never updated, then there will be no download available.
Be aware that there are no download links available for previous versions. If you own version 3.2.1 and this is updated by Reallusion to version 3.2.2 then this is the only version available for you to download. If you don't update to version 4 then your download will be "stuck" at the last available release of 3.
The best, and safest, way to protect your purchase is to always keep copies of the installer files stored on a separate external drive. This can also be useful if you need to roll back to a previous version of the software for any reason.
The software that you purchase at present is "for life", and can be used for as long as you wish.
Gerry
System: Win 10 Pro (21H2), Asus X99-E WS, CPU i7-5930K -3,5 GHz, 32 GB DDR4 2666-16 RAM, NVidia GTX 1080 Ti GPU - 11 GB VRAM(Driver Studio-536.99), Samsung 850 Pro 512 GB SSD, 6 TB HD storage.