Issue While Installing Aras Enterprise search ArasESAgentSetup.msi

           I have installed Innovator 12.0  SP5 and Aras Enterprise search as per the  instruction in the installation guide. I am installing zookeeper, solr and agent on different machine. I am able to install Zookeeper and Solr nodes smoothly. Also confirms the solr installation by localhost:8983/.../ url. I am getting solr dashboard.
          when I try to install ArasESAgentSetup.msi I am getting error as "Internal server error: Can't create user "solradmin"". 

Please help me out regarding the issue.