Recently I experencied "Failed to connect to VMware Lookup Service https://your_vcenter_ip_address:9443 – SSL certificate verification failed" error while accessing vSphere Web Client.
After a brief search I figured out this error seems to be caused by SSL certificate mismatch after a vCenter appliance IP address change (KB: 2033338).
To solve this issue simply login to VMware vCenter Server Appliance located at
Go to Admin, click Toggle certificate setting. Certificate regeneration enabled will switch to yes value.
To apply these changes you need to reboot vCenter virtual appliance. Go to System and click Reboot button.
vCenter requires several minutes to restart (about 10-15 in my case).
After this lapse of time check if every service is back on running.
and you will be able to login to vSphere Web Client