diff --git a/controller/app/src/main/java/org/appdevforall/k2go/install/domain/AnsibleRunOutcome.java b/controller/app/src/main/java/org/appdevforall/k2go/install/domain/AnsibleRunOutcome.java
index 6ec59f2b..0efead42 100644
--- a/controller/app/src/main/java/org/appdevforall/k2go/install/domain/AnsibleRunOutcome.java
+++ b/controller/app/src/main/java/org/appdevforall/k2go/install/domain/AnsibleRunOutcome.java
@@ -15,9 +15,11 @@
 
 public final class AnsibleRunOutcome {
 
-    // Pre-recap failure hints: used ONLY when no PLAY RECAP was seen (Ansible crashed before it
-    // could summarize). When a recap IS present these are ignored, because Ansible prints [ERROR]
-    // and fatal lines for ignored errors too, which are not failures.
+    // Hard crash signatures: Ansible can die printing these yet still exit 0, and a later clean
+    // PLAY RECAP (IIAB emits several intermediate recaps) must NOT hide them, so a crash always fails.
+    private boolean sawCrash = false;
+    // [ERROR] is softer: Ansible prints it for IGNORED errors too (counted in ignored=, not failed=),
+    // so a clean recap overrides it. Used as the verdict only when no recap was seen.
     private boolean sawError = false;
     private boolean sawRecap = false;        // a PLAY RECAP host-summary line appeared
     private boolean recapFailure = false;    // a recap host line reported failed>0 or unreachable>0
@@ -25,9 +27,11 @@ public final class AnsibleRunOutcome {
     /** Feed each output line as it streams from the container. */
     public void observe(String line) {
         if (line == null) return;
-        if (line.contains("[ERROR]")
-                || line.contains("Unable to use multiprocessing")
+        if (line.contains("Unable to use multiprocessing")
                 || line.contains("HEARTBEAT SESSION STOPPED")) {
+            sawCrash = true;
+        }
+        if (line.contains("[ERROR]")) {
             sawError = true;
         }
         // A PLAY RECAP host summary carries BOTH "unreachable=" and "failed=" (every real recap line
@@ -40,10 +44,11 @@ public void observe(String line) {
         }
     }
 
-    /** True if the run failed. A non-zero exit always fails; otherwise trust the PLAY RECAP when
-     *  present, and fall back to the [ERROR]/crash signatures only when no recap was emitted. */
+    /** True if the run failed. A non-zero exit or a hard crash signature always fails; otherwise
+     *  trust the PLAY RECAP when present, and fall back to the [ERROR] signal only with no recap. */
     public boolean failed(int exitCode) {
         if (exitCode != 0) return true;
+        if (sawCrash) return true;
         if (sawRecap) return recapFailure;
         return sawError;
     }
diff --git a/controller/app/src/test/java/org/appdevforall/k2go/install/domain/AnsibleRunOutcomeTest.java b/controller/app/src/test/java/org/appdevforall/k2go/install/domain/AnsibleRunOutcomeTest.java
index b713c8ac..610b9ae1 100644
--- a/controller/app/src/test/java/org/appdevforall/k2go/install/domain/AnsibleRunOutcomeTest.java
+++ b/controller/app/src/test/java/org/appdevforall/k2go/install/domain/AnsibleRunOutcomeTest.java
@@ -72,4 +72,13 @@ public class AnsibleRunOutcomeTest {
         o.observe("127.0.0.1 : ok=1 changed=0 unreachable=1 failed=0 skipped=0 rescued=0 ignored=0");
         assertTrue(o.failed(0));
     }
+
+    @Test public void crashSignatureAfterCleanRecap_isStillFailed() {
+        // K2GO-450: IIAB emits several intermediate PLAY RECAPs, so a hard crash can follow an early
+        // clean recap. A clean recap only overrides the softer [ERROR], never a crash signature.
+        AnsibleRunOutcome o = new AnsibleRunOutcome();
+        o.observe("127.0.0.1 : ok=5 changed=2 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0");
+        o.observe("ERROR! Unable to use multiprocessing, see stderr (lack of access to /dev/shm)");
+        assertTrue(o.failed(0));
+    }
 }