diff --git a/supacode/Features/DiffView/DiffWindowContentView.swift b/supacode/Features/DiffView/DiffWindowContentView.swift
index 882b3821..7afeb91e 100644
--- a/supacode/Features/DiffView/DiffWindowContentView.swift
+++ b/supacode/Features/DiffView/DiffWindowContentView.swift
@@ -105,8 +105,13 @@ struct DiffWindowContentView: View {
             showsFileHeaders: false,
           ),
           onEvent: { event in
-            if case .didRender = event {
+            switch event {
+            case .didRender:
               state.markDiffRendered()
+            case .didFail(let error):
+              state.markDiffFailed(error)
+            default:
+              break
             }
           }
         )
@@ -117,9 +122,23 @@ struct DiffWindowContentView: View {
               .padding(12)
               .background(.regularMaterial, in: Circle())
               .transition(.opacity)
+          } else if let renderError = state.renderError {
+            VStack(spacing: 6) {
+              Image(systemName: "exclamationmark.triangle")
+                .foregroundStyle(.orange)
+                .accessibilityHidden(true)
+              Text(renderError.message)
+                .font(.caption)
+                .multilineTextAlignment(.center)
+            }
+            .padding(12)
+            .frame(maxWidth: 240)
+            .background(.regularMaterial, in: RoundedRectangle(cornerRadius: 8))
+            .transition(.opacity)
           }
         }
         .animation(.easeInOut(duration: 0.15), value: state.isRenderingDiff)
+        .animation(.easeInOut(duration: 0.15), value: state.renderError)
       } else if state.isLoadingFiles {
         ProgressView()
           .frame(maxWidth: .infinity, maxHeight: .infinity)
diff --git a/supacode/Features/DiffView/DiffWindowState.swift b/supacode/Features/DiffView/DiffWindowState.swift
index f373b402..49d63689 100644
--- a/supacode/Features/DiffView/DiffWindowState.swift
+++ b/supacode/Features/DiffView/DiffWindowState.swift
@@ -15,6 +15,10 @@ final class DiffWindowState {
   /// large files, since diffing/painting happens on the JS side. Cleared by
   /// `markDiffRendered()` once the view reports its `didRender` event.
   var isRenderingDiff = false
+  /// Set by `markDiffFailed(_:)` when `DiffView` reports a `.didFail` event, so
+  /// the render-in-progress indicator doesn't stay stuck forever. Cleared as soon
+  /// as a new document starts rendering.
+  var renderError: DiffError?
 
   private var documentCache: [String: DiffDocument] = [:]
   private var loadTask: Task<Void, Never>?
@@ -87,9 +91,19 @@ final class DiffWindowState {
     isRenderingDiff = false
   }
 
+  /// Called by the view once `DiffView` reports its `didFail` event, so the
+  /// loading indicator doesn't stay stuck forever when a render fails.
+  func markDiffFailed(_ error: DiffError) {
+    isRenderingDiff = false
+    renderError = error
+  }
+
   private func updateDiffDocument(_ newDocument: DiffDocument?) {
     guard newDocument != diffDocument else { return }
     isRenderingDiff = newDocument != nil
+    if isRenderingDiff {
+      renderError = nil
+    }
     diffDocument = newDocument
   }
 
diff --git a/supacodeTests/DiffWindowStateTests.swift b/supacodeTests/DiffWindowStateTests.swift
index b40cfb3a..aa28c298 100644
--- a/supacodeTests/DiffWindowStateTests.swift
+++ b/supacodeTests/DiffWindowStateTests.swift
@@ -266,6 +266,45 @@ struct DiffWindowStateTests {
 
     #expect(state.diffDocument != docB)
   }
+
+  @Test func markDiffFailedClearsRenderingAndStoresError() async {
+    let fileA = DiffChangedFile(status: .modified, oldPath: "a.swift", newPath: "a.swift")
+    let docA = DiffDocument(files: [], title: "a")
+    let state = DiffWindowState(
+      fetchChangedFiles: { _ in [fileA] },
+      loadDiffDocument: { _, _ in docA }
+    )
+    await state.loadAllFiles(worktreeURL: URL(fileURLWithPath: "/tmp"))
+    #expect(state.isRenderingDiff)
+
+    let error = DiffError(code: "render_failed", message: "boom")
+    state.markDiffFailed(error)
+
+    #expect(!state.isRenderingDiff)
+    #expect(state.renderError == error)
+  }
+
+  @Test func selectingANewFileClearsAPriorRenderError() async {
+    let fileA = DiffChangedFile(status: .modified, oldPath: "a.swift", newPath: "a.swift")
+    let fileB = DiffChangedFile(status: .modified, oldPath: "b.swift", newPath: "b.swift")
+    let docA = DiffDocument(files: [], title: "a")
+    let docB = DiffDocument(files: [], title: "b")
+    let docs = ["a.swift": docA, "b.swift": docB]
+    let clock = TestClock()
+    let state = DiffWindowState(
+      fetchChangedFiles: { _ in [fileA, fileB] },
+      loadDiffDocument: { file, _ in docs[file.id]! },
+      clock: clock
+    )
+    await state.loadAllFiles(worktreeURL: URL(fileURLWithPath: "/tmp"))
+    state.markDiffFailed(DiffError(code: "render_failed", message: "boom"))
+    #expect(state.renderError != nil)
+
+    state.selectFile(fileB)
+    await advanceSelectDebounce(clock)
+
+    #expect(state.renderError == nil)
+  }
 }
 
 @MainActor