Unable to install Remote Desktop Session Host role on windows server 2012 R2

First

Disabled system firewall and third party security software on RD SH servers then test again.

If the issue persists, please check event logs to see whether more clues are logged.

If no useful event can be found, you may enable RDMSDeploymentUI and RDMSUI-trace logs

and follow that steps:

1.On the Remote Desktop (RD) Connection Broker server, create the following registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\RDMS

2.Create the following two registry entries under the registry key:

Server