diff --git a/backend/src/main/java/org/raddatz/familienarchiv/service/SenderModelService.java b/backend/src/main/java/org/raddatz/familienarchiv/service/SenderModelService.java
index d02caad4..e7881474 100644
--- a/backend/src/main/java/org/raddatz/familienarchiv/service/SenderModelService.java
+++ b/backend/src/main/java/org/raddatz/familienarchiv/service/SenderModelService.java
@@ -154,7 +154,8 @@ public class SenderModelService {
 
         OcrTrainingRun run = Objects.requireNonNull(txTemplate.execute(status ->
                 trainingRunRepository.findFirstByPersonIdAndStatus(personId, TrainingStatus.RUNNING)
-                        .orElseThrow(() -> new IllegalStateException(
+                        .orElseThrow(() -> DomainException.internal(
+                                ErrorCode.OCR_TRAINING_CONFLICT,
                                 "Expected RUNNING row for person " + personId + " but none found"))));
 
         String runId = run.getId().toString();
diff --git a/backend/src/test/java/org/raddatz/familienarchiv/service/SenderModelServiceTest.java b/backend/src/test/java/org/raddatz/familienarchiv/service/SenderModelServiceTest.java
index 20086e10..4f18701a 100644
--- a/backend/src/test/java/org/raddatz/familienarchiv/service/SenderModelServiceTest.java
+++ b/backend/src/test/java/org/raddatz/familienarchiv/service/SenderModelServiceTest.java
@@ -297,6 +297,16 @@ class SenderModelServiceTest {
         verify(senderModelRepository, never()).save(any());
     }
 
+    @Test
+    void triggerSenderTraining_throwsDomainException_whenRunningRowMissingAfterDispatch() {
+        when(trainingRunRepository.findFirstByPersonIdAndStatus(personId, TrainingStatus.RUNNING))
+                .thenReturn(Optional.empty());
+
+        org.assertj.core.api.Assertions.assertThatThrownBy(
+                () -> service.triggerSenderTraining(personId, 0))
+                .isInstanceOf(DomainException.class);
+    }
+
     // ─── triggerSenderTraining — queue promotion ──────────────────────────────
 
     // ─── triggerManualSenderTraining ──────────────────────────────────────────