Analyzer throws exceptions during build

**Describe the bug**
When building our solution I get a couple of exceptions in the build output logs.
`112>CSC : warning AD0001: Analyzer 'Csla.Analyzers.EvaluatePropertiesForSimplicityAnalyzer' threw an exception of type 'System.ArgumentNullException' with message 'Value cannot be null.`

**Version and Platform**
CSLA version: 9.0
OS: Windows

**Additional context**
Doing a build or rebuild all
