Impersonating Anyone From Code Yields 401: Unauthorized on next PSI call

Hello Everyone,

I am running an event handler and I am trying to impersonate an administrator, but evertime I make a PSI call as that account, I get a 401 unauthorized error.

By default, the event runs under the spFarm account, and when I just use default credentials everything works fine, but as soon as I try to impersonate this spFarm user, PSI calls fail.

//get the user GUID
Guid userGuid = new Guid( LoadParameterValueFromXML( settingsXml, "userGuid" ) );

//Get the domain name
string domainName = LoadParameterValueFromXML( settingsXml, "domainName" );
//get the site Guid 
SPSite pwaSite = new SPSite( PWAUrl );
Guid siteUID = pwaSite.ID;
//set the impersonation
ProjectDerived.SetImpersonationContext( true, domainName, userGuid, Guid.NewGuid(), siteUID );
SecurityDerived.SetImpersonationContext( true, domainName, userGuid, Guid.NewGuid(), siteUID );
LookupTableDerived.SetImpersonationContext( true, domainName, userGuid, Guid.NewGuid(), siteUID );

After this code I make a call to read project entities and that is when I get the unauthorized error. Yes, I have double checked the domain name and User GUID to ensure they are accurate. Any ideas as to why impersonating anyone, even an admin, will fail?

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