Symptoms
When you attempt to connect to vCenter Server using the vSphere Web Client, you see errors similar to: Could not connect to vCenter Server https://VCENTER_PROD.EXAMPLE.COM:443/sdk Error communicating with lookup service In the C:\ProgramData\VMware\Infrastructure\Inventory Service\Logs\ds.log file, you see the error:ERROR com.vmware.vim.dataservices.provider.util.SetupLocalService] java.lang.IllegalArgumentException: Host name may not be null In the %ProgramData%\VMware\vSphere Web Client\serviceability\logs\vsphere_client_virgo.log file, you see errors similar to:https://VCENTER_PROD.EXAMPLE.COM:12443>/vmwb/logbrowser: Host name may not be nullERROR [ERROR] http-bio-9443-exec-8 System.err java.lang.IllegalArgumentException: Host name may not be nullERROR [ERROR] http-bio-9443-exec-8 com.vmware.loganalyzer.provider.LogBrowserServiceImpl Error when searching service in LookupService, urn:logbrowser:logbrowser java.lang.Exception:https://VCENTER_PROD.EXAMPLE.COM:12443/vmwb/logbrowser: Host name may not be null In the C:\Users\<current user>\AppData\Local\Temp\vminst.log file, you see errors similar to:VMware vSphere Web Client-build-1378905: <MM/DD/YY HH:MM:SS> SSO Registration tool launchedVMware vSphere Web Client-build-1378905: <MM/DD/YY HH:MM:SS> SSO registration tool failed with return code -2VMware vSphere Web Client-build-1378905: <MM/DD/YY HH:MM:SS> Please see vm_ssoreg.log in system temporary folderVMware vSphere Web Client-build-1378905: <MM/DD/YY HH:MM:SS> Lookup Service certificate download failed with return code -2 Res: 29113 In the C:\Users\<current user>\AppData\Local\Temp\ SSOreg.log file, you see entries similar to:[<MM/DD/YY HH:MM:SS>,568 main INFO com.vmware.vim.install.impl.CertificateGetter] Getting SSL certificates for https://VCENTER_VS.vclass.local:7444/lookupservice/sdk[<MM/DD/YY HH:MM:SS>,053 main DEBUG com.vmware.vim.install.impl.CertificateGetter] Establishing Socket Connection to VCENTER_VS.vclass.local/192.168.0.240: 7444th Timeout ice 60000[<MM/DD/YY HH:MM:SS>,396 main ERROR com.vmware.vim.install.cli.commands.CommandArgumentsParser] Host Name May not be null[<MM/DD/YY HH:MM:SS>,398 main INFO com.vmware.vim.install.cli.RegTool] Return code is: Invalid Input
Cause
If the vCenter Server host name contains an underscore, it is considered an invalid host name and that vCenter Server does not appear in the vSphere Web Client.
Resolution
To resolve this issue, change the host name of the vCenter Server so that it does not contain any underscores.For example:If the host name is VCENTER_PROD, rename it to VCENTERPROD or another name without an underscore.
