I am choosing a Small Business Edition license file for my Sitefinity websites and each time I choose a Small Business Edition license file, it is displaying as "Corrupted License File" even though it is a valid license file!
I had the exact problem with the Community Edition about a year ago. I believe I resolved it by downloading the licence manually and selecting the downloaded licence when setting up the project. In my situation the problem was compounded because the link to download licences disappear from my Telerik Account. In my case I had to login with my work account to get the URL and pasted it after logging in with my Community Edition account. Now it appears that the URL requires a querystring associated with the account, so I can't give you the link. But hopefully you won't have that problem since you are using Business not Community Edition.
How are you downloading the licence? The only way I got it to install was by:
1. Log into Telerik website and manually downloaded the licence.
2. Create the sitefinity project using Sitefinity Project Manager.
3. When prompted for a licence specify the one you downloaded in step 1.
One other thing to point out. If you are using a licence for an older version of Sitefinity it won't work. For example the licence for Sitefinity Business Edition 6 will not work if you are installing Sitefinity Business Edition 7. Instead you have to download the version 7 licence.