We encourage all the InstalSystem 4 licence owners to take advantage of the possibility to upgrade their version 4 licences into version 5. After the upgrade, such a licence still gives the opportunity to use InstalSystem 4, but at the same time, it activates the InstalSystem 5 package. The upgrade allows to buy an InstalSystem 5 licence for a better price. It is worth using this opportunity, as the possibility to upgrade InstalSystem 4 licences into InstalSystem 5 will be available only until the end of 2023. After this date, the upgrade for version 4 licences will not be available. Then, for all users, it will be possible to buy new InstalSystem 5 licences for their standard prices.