The Horizon Client installation tries to append an entry to the "hosts" file, which seems to be write protected.

vdmInstUtil: 04/03/20 14:34:53 --- VMAddViewLocalHostEntryToHostsFile() : Adding view-localhost entry to the 'etc\hosts' file.

vdmInstUtil: 04/03/20 14:34:53 File exists: "C:\WINDOWS\system32\Drivers\etc\hosts"

vdmInstUtil: 04/03/20 14:34:53 Searching for '127.0.0.1 view-localhost # view localhost server' in "C:\WINDOWS\system32\Drivers\etc\hosts"

vdmInstUtil: 04/03/20 14:34:53 File exists: "C:\WINDOWS\system32\Drivers\etc\hosts"

vdmInstUtil: 04/03/20 14:34:53 Pattern not found!

vdmInstUtil: 04/03/20 14:34:53 Appending text to file: "C:\WINDOWS\system32\Drivers\etc\hosts"

vdmInstUtil: 04/03/20 14:34:53 ERROR: Failed to open file: "C:\WINDOWS\system32\Drivers\etc\hosts": 13

vdmInstUtil: 04/03/20 14:34:53 ERROR: Failed writing to file "C:\WINDOWS\system32\Drivers\etc\hosts".

vdmInstUtil: 04/03/20 14:34:53 Exiting custom action VMAddViewLocalHostEntryToHostsFile

CustomAction VM_AddViewLocalHostEntryToHostsFile returned actual error code 1603 (note this may not be 100% accurate if translation happened inside sandbox)

That could be caused by UAC (permission issue), or an A/V app which prevents modifications for this file.

You may need to temporarily disable A/V, or try to add the entry (I marked it in red) manually to the hosts file prior to running the Horizon Client setup.

André