Citect did not start because value can not be Null.
Parameter Name :Register Key
Citect did not start because value can not be Null.
Parameter Name :Register Key
From Support Case:
"There was no control client software installed on Anywhere machine that’s why its not working.
Now it’s working fine now."'
So appears customer had not installed Plant SCADA on the Anywhere Server machine. After installing the product, problem resolved.