Symptoms

When trying to deploy a package the user was receiving the following error:

System.NullreferenceException

SmartObject property PackageFile is a required property for selected method LoadPackage. FileName property must be set.
 

Diagnoses

This is a known an tracked issue that happens in clustered Appit environments. The cause here is a desync causing a SmartObject to execute before the required inputs are set.
 

Resolution

Redeploying the package tends to be enough to correct the issue.