diff --git a/base/src/main/java/de/staropensource/sosengine/base/logging/CrashHandler.java b/base/src/main/java/de/staropensource/sosengine/base/logging/CrashHandler.java
index 78b4e14..7397f3e 100644
--- a/base/src/main/java/de/staropensource/sosengine/base/logging/CrashHandler.java
+++ b/base/src/main/java/de/staropensource/sosengine/base/logging/CrashHandler.java
@@ -184,7 +184,11 @@ public final class CrashHandler {
             if (!content.isEmpty())
                 content.append("\n");
 
-            if (map.get(key) instanceof String) {
+            if (map.get(key) == null) {
+                if (indentationSize == 0) content.append("\n");
+                else content.append(" ".repeat(indentationSize)).append("-> ");
+                content.append(key);
+            } else if (map.get(key) instanceof String) {
                 if (indentationSize == 0) content.append("\n");
                 else content.append(" ".repeat(indentationSize)).append("-> ");
                 content.append(key).append(": ").append(map.get(key));