After you have installed the DaaS Agent, you can install the Horizon Agent.
There are three possible scenarios when installing the Horizon Agent:
Install on Windows desktop
Install on Windows server as Personal Desktop (Non-RDSH)
Install on Windows server as RDSH Role
If you have not installed the most recent version of the Horizon Agent, this can cause problems with creating RDS pools. In this case, when you create a new RDS pool, the system can allow you to select HTML Access (Blast) as a protocol, but this selection will not be applied to the pool even though it appears to have been applied successfully.