Execution error on iApp VMware Horizon View Optimized v1.3.0

Hi, I am trying to use iApp (v1.3.0) to configure VMware Horizon View on TMOS 11.6.0 HF6.

It showing error while creating the configuration.

script did not successfully complete: (ltcfg error, can't load class, class:"dns" error: can't load class 
definition from mcpd. This is most likely the result of a failure to load the base system configuration.
To determine the root cause enter "tmsh load sys config" and include the output when the issue is reported.

 while executing

tmsh::modify [string range $args 7 end] "
 ("modify" arm line 1)
 invoked from within
"switch -exact -- [string range $args 0 5] {
 create { tmsh::create [string range $args 7 end] }
 modify { tmsh::modify [string r..."
 (procedure "iapp_conf" line 14)
 invoked from within
"iapp_conf modify sys $svc $title($svc) add \{ $addr_list \}"
 ("foreach" body line 9)
 invoked from within
"foreach svc { dns ntp } {
 set addr_list ""
 foreach item [set ::options__$svc] {
 set addr [join [join $item..." line:1444)

Any help or a point in the right direction would be wonderful! Thanks!