diff --git a/Nodejs/Product/Analysis/Analysis/Analyzer/AnalysisUnit.cs b/Nodejs/Product/Analysis/Analysis/Analyzer/AnalysisUnit.cs
index 39cdf2e4e..7cf38ec99 100644
--- a/Nodejs/Product/Analysis/Analysis/Analyzer/AnalysisUnit.cs
+++ b/Nodejs/Product/Analysis/Analysis/Analyzer/AnalysisUnit.cs
@@ -233,7 +233,8 @@ public override string ToString() {
                 GetHashCode(),
                 Ast != null ? Ast.GetType().Name : "<unknown>",
                 GetType().Name,
-                Ast != null ? Ast.GetStart(ProjectEntry.Tree.LocationResolver) : SourceLocation.Invalid
+                Ast != null && ProjectEntry != null && ProjectEntry.Tree != null ?
+                    Ast.GetStart(ProjectEntry.Tree.LocationResolver) : SourceLocation.Invalid
             );
         }