Back in the days of AdminStudio 11.0, AdminStudio had multiple optional packs like Virtualization Pack, Application Compatibility Pack, Complete Pack etc. Compatibility Solver functionality was exclusive to the Application Compatibility Pack and since you mentioned that you had Virtualization Pack, you would not have access to Compatibility Solver functionality.
In the recent versions of AdminStudio, all the optional packs have been rolled into the main edition(Enterprise, Professional and Standard). So, the functionalities which were exclusive to a particular pack in the past, will now be available in the main edition itself. However, it is important to note that Compatibility Solver functionality will be available in Enterprise and Professional editions of AdminStudio. If you wish to run compatibility solver and take benefit of lot of other powerful and valuable features added in the product in all the later versions, then I would recommend upgrading AdminStudio to the latest version. Also, just so you know AdminStudio 11.0 is End of Life - https://docs.flexera.com/eol/adminstudio.htm.
