.lic or .license file types are designed to be read by the program that they are licensing. They cannot be "viewed" the same way that a word or PDF document can be.
This is a security measure, because if you could open a license file in notepad or similar, you would be able to edit the file. If you could edit the file, people wouldn't need to buy licenses because they would just save the file again but with new details (e.g. expires in 2099 or has unlimited users or whatever the use case may be).
For PaperCut licensing, the file should be sent to the technician or end user who will be authorised to log in to the PaperCut admin interface and apply the license by uploading the file through the About section. Look here for more information.