Each time you upgrade your Citrix product, you should also upgrade the Citrix License Server. Each time a new License Server is released, it may contain better security, fixes to known issues, and so on. In some cases, new versions of the Citrix product will not work with older versions of the License Server.
Note: New versions of the License Server are compatible with older versions of the product and old licenses.
If you are a current Citrix Subscription Advantage member, you are eligible to version upgrade to the latest release of Citrix products and upgrade your existing licenses to the license system used by these products.
Version Upgrade means the movement from any previous version of a product to the newest version of the product (for example, moving from XenDesktop 5.6 to XenDesktop 7.x).
Edition Upgrade means the purchase of a higher edition level of a product (for example, you currently have Enterprise Edition and you purchase an upgrade to Platinum Edition).