diff --git a/sonaranalyzer-dotnet/src/SonarAnalyzer.CSharp/Rules/StringFormatValidator.cs b/sonaranalyzer-dotnet/src/SonarAnalyzer.CSharp/Rules/StringFormatValidator.cs
index a127f65d050..35ff9272fc3 100644
--- a/sonaranalyzer-dotnet/src/SonarAnalyzer.CSharp/Rules/StringFormatValidator.cs
+++ b/sonaranalyzer-dotnet/src/SonarAnalyzer.CSharp/Rules/StringFormatValidator.cs
@@ -435,14 +435,15 @@ public static FormatStringArgument Create(ExpressionSyntax expression, SemanticM
             {
                 var type = semanticModel.GetTypeInfo(expression).Type;
                 var arraySize = -1;
-                if (type.Is(TypeKind.Array))
+                if (type != null && type.Is(TypeKind.Array))
                 {
                     if (expression is ImplicitArrayCreationExpressionSyntax implicitArray)
                     {
                         arraySize = implicitArray.Initializer.Expressions.Count;
                     }
 
-                    if (expression is ArrayCreationExpressionSyntax array)
+                    if (expression is ArrayCreationExpressionSyntax array &&
+                        array.Initializer != null)
                     {
                         arraySize = array.Initializer.Expressions.Count;
                     }
diff --git a/sonaranalyzer-dotnet/tests/SonarAnalyzer.UnitTest/Rules/StringFormatValidatorTest.cs b/sonaranalyzer-dotnet/tests/SonarAnalyzer.UnitTest/Rules/StringFormatValidatorTest.cs
index 20e15525f91..0fdab2795f4 100644
--- a/sonaranalyzer-dotnet/tests/SonarAnalyzer.UnitTest/Rules/StringFormatValidatorTest.cs
+++ b/sonaranalyzer-dotnet/tests/SonarAnalyzer.UnitTest/Rules/StringFormatValidatorTest.cs
@@ -58,5 +58,14 @@ public void StringFormatTypoFreeValidator()
                 new StringFormatValidator(),
                 workingOptions);
         }
+
+        [TestMethod]
+        [TestCategory("Rule")]
+        public void StringFormatEdgeCasesValidator()
+        {
+            Verifier.VerifyAnalyzer(@"TestCases\StringFormatEdgeCasesValidator.cs",
+                new StringFormatValidator(),
+                workingOptions);
+        }
     }
 }
diff --git a/sonaranalyzer-dotnet/tests/SonarAnalyzer.UnitTest/TestCases/StringFormatEdgeCasesValidator.cs b/sonaranalyzer-dotnet/tests/SonarAnalyzer.UnitTest/TestCases/StringFormatEdgeCasesValidator.cs
new file mode 100644
index 00000000000..1ac2959cf70
--- /dev/null
+++ b/sonaranalyzer-dotnet/tests/SonarAnalyzer.UnitTest/TestCases/StringFormatEdgeCasesValidator.cs
@@ -0,0 +1,26 @@
+using System.Text;
+
+namespace Tests.Diagnostics
+{
+    public class StringFormatEdgeCasesValidator
+    {
+        // See https://github.com/SonarSource/sonar-dotnet/issues/2392
+        void EdgeCases(string bar)
+        {
+            var builder = new StringBuilder();
+            builder.AppendFormat("&invoice={0}", Foo(bar));
+            builder.AppendFormat("&invoice={0}", new object[0]);
+            builder.AppendFormat("&invoice={0}", new object[1] { 1 });
+            builder.AppendFormat("&invoice={0}", new [] { 1 });
+            builder.AppendFormat("&rm=2", new object[0]);
+            builder.AppendFormat("&rm=2", new[] { 1 }); // Noncompliant
+            builder.AppendFormat("&rm=2", new object[0] { } ); // Noncompliant
+            builder.AppendFormat("&rm=2", new object[1] { "a" } ); // Noncompliant
+        }
+
+        string Foo(string bar)
+        {
+            return "";
+        }
+    }
+}