Could not find this item

Recently I noticed some wired behavior of my test file server.
Whenever I remove a folder, the folder icon remains there, even though it deleted, but it's still showing.
if I double click on it, the folder open and then automatically exit "Go back one level up".
If I try to remove the folder again, I got the message below

Using Sysinternal Procmon.exe, I got the following message when trying to remove the folder. NAME NOT FOUND.
I noticed also using the CMD the folder name is ending with white space.
My folder name is VDI1, using the CMD with auto-complete I got this:
rd "vdi1 "

FIX:
To remove the file use the following command to remove the folder
rd "\\?\d:\Shares\Home\vdi1 "
use the TAB while typing the path for auto-complete, as the end of the folder contains white space.
using this way. I was able to remove the folder.

Cloud Witness option is disabled in Failover Cluster

I had my SQL Server Cluster AG up and running and using the local File Witness Sharing, but later on I decided to move witness to the Azure cloud as I need to expand my cluster to a DR Site.
When I try to change the cluster quorum setting to I got this

There is no indication why, nothing in the windows event log, or cluster log.
I tried to use Powershell to change the setting using the command in the following URL

Set-ClusterQuorum -CloudWitness -AccountName -AccessKey
But I got the following error message

Set-ClusterQuorum : The current cluster functional level does not support cloud witness. Please update your cluster
nodes to Windows Server 2016.
At line:1 char:1
+ Set-ClusterQuorum -CloudWitness -AccountName -AccessKey 

In Windows 2016, its possible to have multiple OS in the same cluster like Windows 2012 and 2016, this will force the cluster to operate in a lower function level for the compatibility reasons.
To address this issue we need to raise the Cluster Function Level using the following command 
Update-ClusterFunctionalLevel and press enter
after running this command and confirm the changes to the function level, I was able to configure the cloud witness via the GUI :)