SPSecurityContext.WindowsIdentity: Could not retrieve a valid windows identity for NTName='domain\username', UPN='username@domain.com'. UPN is required when Kerberos constrained delegation is used.

Hi,

We were getting the below error when we were trying to save the wiki page through SharePoint ribbon.

Error:

SPSecurityContext.WindowsIdentity: Could not retrieve a valid windows identity for NTName='domain\username', UPN='username@domain.com'. UPN is required when Kerberos constrained delegation is used.  

Finally our teammate has found the solution i.e.

In the page layout that we were using we had commented the below table due to certain changes.

At the same time we had commented the table where we were referring to, there it started creating a problem.

Now had uncommented the area and changes as display property to none as below