FIX: Show scenario run failure details

frontend/src/components/Scenarios/ScenarioRunPage.test.tsx

@@ -423,6 +423,38 @@ describe('ScenarioRunPage', () => {
     expect(screen.getByText(/showing the last successfully loaded progress/i)).toBeInTheDocument()
   })
 
+  it('shows the persisted failure reason and type for failed runs', () => {
+    mockHookState(makeState({
+      run: {
+        ...makeState().run!,
+        status: 'FAILED',
+        error: 'Scenario initialization failed.',
+        error_type: 'ValueError',
+      },
+    }))
+
+    renderPage()
+
+    expect(screen.getByText(
+      /Run failed \(ValueError\): Scenario initialization failed\. Finished executions remain available below\./,
+    )).toBeInTheDocument()
+  })
+
+  it('shows a generic failure message for legacy runs without error details', () => {
+    mockHookState(makeState({
+      run: {
+        ...makeState().run!,
+        status: 'FAILED',
+      },
+    }))
+
+    renderPage()
+
+    expect(screen.getByText(
+      /This run ended before all planned executable units completed\. Finished executions remain available below\./,
+    )).toBeInTheDocument()
+  })
+
   it('cancels after confirmation and immediately applies the returned terminal state', async () => {
     const user = userEvent.setup()
     const cancelledRun = {

frontend/src/components/Scenarios/ScenarioRunPage.tsx

@@ -402,7 +402,7 @@ function ScenarioRunPageContent({ scenarioResultId, attackResultId }: ScenarioRu
         {run.status === 'FAILED' && (
           <MessageBar intent="error">
             <MessageBarBody>
-              This run ended before all planned executable units completed. Finished executions remain available below.
+              {formatRunFailure(run)}
             </MessageBarBody>
           </MessageBar>
         )}
@@ -789,6 +789,20 @@ function formatRunState(status: string): string {
   return status.toLowerCase().replace('_', ' ').replace(/^\w/, (letter) => letter.toUpperCase())
 }
 
+function formatRunFailure(run: ScenarioProgressHeader): string {
+  const completedResultsMessage = 'Finished executions remain available below.'
+  if (run.error_type && run.error) {
+    return `Run failed (${run.error_type}): ${run.error} ${completedResultsMessage}`
+  }
+  if (run.error) {
+    return `Run failed: ${run.error} ${completedResultsMessage}`
+  }
+  if (run.error_type) {
+    return `Run failed (${run.error_type}). ${completedResultsMessage}`
+  }
+  return `This run ended before all planned executable units completed. ${completedResultsMessage}`
+}
+
 function statusIcon(status: ScenarioRunState): React.ReactElement {
   if (status === 'COMPLETED') {
     return <CheckmarkCircleRegular />

frontend/src/types/index.ts

@@ -787,6 +787,8 @@ export interface ScenarioProgressHeader {
   status: ScenarioRunState
   created_at: string
   completed_at?: string | null
+  error?: string | null
+  error_type?: string | null
   pyrit_version?: string | null
   target?: ScenarioTargetSummary | null
   techniques_used?: string[]

pyrit/backend/services/scenario_run_service.py

@@ -1255,6 +1255,8 @@ def get_run_progress_from_storage(
                 status=header_result.scenario_run_state,
                 created_at=header_result.creation_time,
                 completed_at=header_result.completion_time if terminal else None,
+                error=header_result.error_message,
+                error_type=header_result.error_type,
                 pyrit_version=header_result.pyrit_version,
                 target=target,
                 techniques_used=techniques_used,

pyrit/models/scenario_progress.py

@@ -101,6 +101,8 @@ class ScenarioProgressHeader(BaseModel):
     status: ScenarioRunState
     created_at: datetime
     completed_at: datetime | None = None
+    error: str | None = None
+    error_type: str | None = None
     pyrit_version: str | None = None
     target: "ScenarioTargetSummary | None" = None
     techniques_used: list[str] = Field(default_factory=list)

tests/unit/backend/test_scenario_run_service.py

@@ -2309,6 +2309,29 @@ def test_get_progress_uses_lightweight_queries_without_full_hydration(mock_memor
     assert str(header.id) not in service._active_tasks
 
 
+def test_get_progress_maps_persisted_failure_details(mock_memory) -> None:
+    plan = ScenarioRunPlan(atomic_groups=[], seed_groups=[], scenario_registry_name="test.scenario")
+    header = make_scenario_result(
+        attack_results={},
+        scenario_run_state=ScenarioRunState.FAILED,
+        error_message="Scenario initialization failed.",
+        error_type="ValueError",
+        metadata={SCENARIO_RUN_PLAN_METADATA_KEY: plan.model_dump(mode="json")},
+    )
+    mock_memory.get_scenario_result_header.return_value = header
+    mock_memory.get_scenario_attack_result_deltas.return_value = ([], False)
+
+    progress = ScenarioRunService().get_run_progress(
+        scenario_result_id=str(header.id),
+        since=None,
+        limit=25,
+    )
+
+    assert progress is not None
+    assert progress.run.error == "Scenario initialization failed."
+    assert progress.run.error_type == "ValueError"
+
+
 def test_get_progress_cache_only_maps_new_storage_rows(mock_memory) -> None:
     seed_group_ids = ["seed-1", "seed-2"]
     plan = ScenarioRunPlan(