Ensure that the Secondary NetScaler node is accessible using HTTPS://<NSIP>/. This is required for the SIM communication to work.
Important: If unable to communicate with the NetScaler using HTTPS, browse to the NetScaler using HTTP, and go to: Configuration > Traffic Management > SSL > FIPS > Action > Import. From the Import as a FIPS Key window, specify the default key located in /netscaler/ssl directory.
After the key is imported, it can be seen under FIPS node without a Modulus.