The error "Horizon Connection Server license key is invalid" typically occurs due to a mismatch between the and the license type , or issues with the licensing portal transition . Common Causes
The license file contains a cryptographic timestamp. If your Connection Server’s system clock drifts more than 5 minutes from the VMware license validation server (or if the clock is set to a past date), the digital signature fails, rendering the key invalid. horizon connection server license key is invalid