If you haven't upgraded the CIMC version then you'll have difficulties accessing the server. The following workaround might help overcoming the situation.
(Adjust the url to your environment)
https://<CIMC_IP>/kvm.jnlp?cimcAddr=<CIMC_IP>&tkn1=<CIMC_username>&tkn2=<CIMC_Password>
This would download a jnlp file that will open a KVM connection to the server. If you face issues connecting to Java KVM then edit the downloaded jnlp file and add the real username and password in the relevant arguments.
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