Alrighty then, now we are able to fixate on that the VC is able to connect properly, but the error happens when any action pertaining to the 248.6 server is triggered.
1. So let us take care of the esxi server side. Can you let us know if the server is under any AD configuration or is running any workloads?
2. From the vpxa.log of the server, check the activity by tail -f /var/log/vpxa.log when you click applications resource pool.
3. Instead of from VC, try opening the server 248.6 from a vsphere client only and check, if you are able to manage or view any properties like vms, licenses, network.