VMware vSAN 8.x
vSAN Standard license does not support RAID5/RAID6 vSAN storage policy. If there are objects in the cluster that use RAID5/RAID6 storage policy, then this error is expected during assignment of the vSAN Standard License to this vSAN cluster.
Using the ESXi host's SSH, use command to capture every vSAN object in the cluster: #esxcli vsan debug object list --all > /tmp/objectlist.txt
The produced object file /tmp/objectlist.txt contains RAID5/RAID6 vSAN objects :
Any vSAN objects using RAID5/RAID6 storage policy needs to be changed to RAID1.
Note: If the issue still persists, restart "vsanmgmtd" service on all hosts in vSAN cluster. Use the below commands,
#/etc/init.d/vsanmgmtd stop
#/etc/init.d/vsanmgmtd start
#/etc/init.d/vsanmgmtd status
Post Restart of vsanmgmtd service, vSAN License can be assigned.
For More details on Licenses and its features refer vSAN License comparison.