You can run two instances of license_server.exe at the same. You simply need to have two separate folders such as c:\ errapool019 and c:\ errapool020. Each folder should have its own copy of license_server.exe and its own collection of licenses. Users can request version 019 licenses of TerraScan and version 020 licenses of Terrasolid products from the Terra License Manager. This concurrent use can only last for a few months. Version 019 pool licenses are only valid until 28Feb2020. Version 020 pool licenses will be valid until 31Mar2021. And so on. One exception this year is that v019 products may be run using a v020 license.