You are installing XenApp 6 onto a Windows Server, XenApp and the License Server pass, but the Web Interface install fails. You check the installation logs and you see an error similar to this.
XenApp Server Role Manager\Startup\StartupIndicator.exe’ exited with error code
This is a confusing error that can and will baffle you till your hair falls out…
I bet you are logged in as a user other than a true local administrator aren’t you? Log off, and log in as a local administrator, finish the install. That easy.