No version of Horizon 6.x support Server 2016. You either need to upgrade to 7.x or stick with one of the supported server OS.
Supported Operating Systems for View Connection Server
Operating System Support for View Connection Server
Operating System | Version | Edition |
|---|---|---|
Windows Server 2008 R2 SP1 | 64-bit | Standard Enterprise Datacenter |
Windows Server 2012 R2 | 64-bit | Standard Datacenter |