To troubleshoot issues with the vCenter web client not starting.
The permissions are incorrect for the log files in the /var/log/vmware/lookupsvc directory. These files should be owned by the lookupsvc user and group, and not root. Since the lookupsvc cannot write to it's log files due to permissions errors the lookupsvc will not start. This may be caused by an old version of this STIG DISA STIG VMware vSphere 7.0 Lookup Service v1r2 STIG ID VCLU-70-000007 being applied to the vCenter server.
Change permissions of the log files in the /var/log/vmware/lookupsvc/ directory to be owned by the lookupsvc user and group. Then start all vCenter services. The lookupsvc along with other services should all start.
# chmod o-w /var/log/vmware/lookupsvc/<file>
# chown lookupsvc:lookupsvc /var/log/vmware/lookupsvc/<file>
# service-control --start --all
There is no workaround the lookupsvc will not start if it cannot write to it's necessary logs.
The vSphere web client will be inaccessible until the issue is resolved.