Your Website states that:
The maximum number of prior file versions you can access corresponds to your Box account type:

Personal Free - 1 Version

This simply isn't true, and I have argued this in a ticket and with a live agent, but the statement implies you can access a prior version of your file.

Definition of Prior is "earlier in time or order" so this makes your statement false as you cannot access anything but the CURRENT version in the Free version.

I would suggest the wording:
The maximum number of file versions you can access corresponds to your Box account type:

Personal Free - current version only

Furthermore, make the web access more clear about this, as when you look at a file it says there are 2 versions with their dates, but in a Free account, when you try to retrieve the older file you get the error
"Server error
File versions could not be retrieved.
No prior versions are available for this file"
Which leads you (like I did) to raise a ticket to find out why!

Even better, allow Free account to have access to one prior version, like some of your rivals!