I am also seeing this with ONTAP 8.2.3 and Toolkit version 3.2.1 which is supposed to fix this.  Here is the error:

Add-NcFileDirectorySecurityPolicyTask -Name $policygroup -Path $JunctionPath -NtfsMode propagate -NtfsSecurityDescriptor $securitydescriptor -SecurityType ntfs -VserverContext $VserverName

Add-NcFileDirectorySecurityPolicyTask : Invalid value specified for "ntfs-sd" element within "file-directory-security-policy-task-add": " ".

At line:1 char:1

+ Add-NcFileDirectorySecurityPolicyTask -Name $policygroup -Path $JunctionPath -Nt ...

+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

+ CategoryInfo : InvalidOperation: (prdc-ramp-01:NcController) [Add-NcFileDirectorySecurityPolicyTask], EINVALIDINPUTERROR

+ FullyQualifiedErrorId : ApiException,DataONTAP.C.PowerShell.SDK.Cmdlets.FileDirectorySecurity.AddNcFileDirectorySecurityPolicyTask

PS L:\> Get-NaToolkitVersion

Major Minor Build Revision

----- ----- ----- --------

3 2 1 68

This is breaking a WFA workflow in my customers environment.