The license file is always called Sitefinity.lic, however there are different license files for each release (4.1, 4.2, 4.4, 4.3).
In the project manager you will be able to see the version of the project under the column Sitefinity version. You will need a license for that version.
A license file can be downloaded from your client account -> Manage Sitefinity keys and donwload a license for the version your project is using.
If you use a license file that is not for the currently used version it will throw error "wrong product version".
the Telerik team
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items