If you are using HTML version for vCenter administration then you see update manager tab is missing if vCenter is windows based. This is an expected behavior with HTML client as per release note of version 6.7.
Note: Using Update Manager functionality in the vSphere Client (HTML5-based GUI) is only supported for Update Manager that runs in the vCenter Server Appliance
HTML client when vCenter is appliance based.
HTML client when vCenter is windows based.
You may see expected lines logs
C:\ProgramData\VMware\vCenterServer\logs\vsphere-client\logs\vsphere_client_virgo.log
[INFO ] plugin-validation1 com.vmware.vise.extensionfw.impl.OsgiUsageValidationService End RequireBundleUsageCheck on com.vmware.vcIntegrity:6.7.0.41422 [INFO ] plugin-validation1 com.vmware.vise.extensionfw.impl.OsgiUsageValidationService Begin UnversionedPackageExportCheck on com.vmware.vcIntegrity:6.7.0.41422 [INFO ] plugin-validation1 com.vmware.vise.extensionfw.impl.OsgiUsageValidationService End UnversionedPackageExportCheck on com.vmware.vcIntegrity:6.7.0.41422 [INFO ] plugin-validation1 com.vmware.vise.extensionfw.impl.OsgiUsageValidationService Begin UnversionedPackageImportCheck on com.vmware.vcIntegrity:6.7.0.41422 [INFO ] plugin-validation1 com.vmware.vise.extensionfw.impl.OsgiUsageValidationService End UnversionedPackageImportCheck on com.vmware.vcIntegrity:6.7.0.41422 [INFO ] plugin-validation1 com.vmware.vise.extensionfw.impl.OsgiUsageValidationService Begin NestedLibPackageExportCheck on com.vmware.vcIntegrity:6.7.0.41422 [INFO ] plugin-validation1 com.vmware.vise.extensionfw.impl.OsgiUsageValidationService End NestedLibPackageExportCheck on com.vmware.vcIntegrity:6.7.0.41422 [INFO ] plugin-validation1 com.vmware.vise.extensionfw.impl.OsgiUsageValidationService Begin NestedLibMultiUsageCheck on com.vmware.vcIntegrity:6.7.0.41422 [INFO ] plugin-validation1 com.vmware.vise.extensionfw.impl.OsgiUsageValidationService End NestedLibMultiUsageCheck on com.vmware.vcIntegrity:6.7.0.41422 [INFO ] plugin-validation1 com.vmware.vise.extensionfw.impl.OsgiUsageValidationService Begin ClashingPluginsCheck on com.vmware.vcIntegrity:6.7.0.41422 [INFO ] plugin-validation1 com.vmware.vise.extensionfw.impl.OsgiUsageValidationService End ClashingPluginsCheck on com.vmware.vcIntegrity:6.7.0.41422 [INFO ] plugin-validation1 com.vmware.vise.extensionfw.impl.OsgiUsageValidationService Begin PluginPackageGlobalScopeCheck on com.vmware.vcIntegrity:6.7.0.41422 [INFO ] plugin-validation1 com.vmware.vise.extensionfw.impl.OsgiUsageValidationService End PluginPackageGlobalScopeCheck on com.vmware.vcIntegrity:6.7.0.41422 [INFO ] plugin-validation1 com.vmware.vise.extensionfw.impl.OsgiUsageValidationService Finished validating com.vmware.vcIntegrity:6.7.0.41422
If you using windows based vCenter and wants to use update manager then use web client (flex client).