Try restarting Web-Client services ones, run below commands in VCSA
"service-control --stop vsphere-client"
"service-control --start vsphere-client"
If it is still not working check vigro log file to see is there any error while deploying logbrowser plugin package.
Log file can be found at /storage/log/vmware/vsphere-client/logs/vsphere_client_virgo.log