diff --git a/src/Titanium.Inspector/Services/SessionArchive.cs b/src/Titanium.Inspector/Services/SessionArchive.cs
index db10e0c30..5fbec2a3b 100644
--- a/src/Titanium.Inspector/Services/SessionArchive.cs
+++ b/src/Titanium.Inspector/Services/SessionArchive.cs
@@ -66,7 +66,7 @@ public static async Task ExportNativeArchiveAsync(IEnumerable<SessionSnapshot> s
             {
                 ct.ThrowIfCancellationRequested();
                 var entry = zip.CreateEntry($"session-{index:D5}.json");
-                await using var stream = await entry.OpenAsync(ct);
+                await using var stream = entry.Open();
                 await JsonSerializer.SerializeAsync(stream, session, cancellationToken: ct);
                 index++;
             }
@@ -82,7 +82,7 @@ public static async Task<List<SessionSnapshot>> ImportNativeArchiveAsync(string
             zipPath,
             FileMode.Open,
             FileAccess.Read,
-            FileShare.Read,
+            FileShare.ReadWrite | FileShare.Delete,
             bufferSize: 4096,
             FileOptions.Asynchronous | FileOptions.SequentialScan);
         using var zip = new ZipArchive(fs, ZipArchiveMode.Read, leaveOpen: true);
@@ -94,7 +94,7 @@ public static async Task<List<SessionSnapshot>> ImportNativeArchiveAsync(string
                 continue;
             }
 
-            await using var stream = await entry.OpenAsync(ct);
+            await using var stream = entry.Open();
             var snap = await JsonSerializer.DeserializeAsync<SessionSnapshot>(stream, cancellationToken: ct);
             if (snap is not null)
             {
diff --git a/src/Titanium.Inspector/ViewModels/MainWindowViewModel.cs b/src/Titanium.Inspector/ViewModels/MainWindowViewModel.cs
index 38c652a96..e185e63ba 100644
--- a/src/Titanium.Inspector/ViewModels/MainWindowViewModel.cs
+++ b/src/Titanium.Inspector/ViewModels/MainWindowViewModel.cs
@@ -1913,8 +1913,16 @@ private async Task ExportArchiveAsync()
             return;
         }
 
-        await SessionArchive.ExportNativeArchiveAsync(_all, path);
-        StatusText = $"Exported {_all.Count} sessions to {path}";
+        try
+        {
+            // SessionArchive runs zip IO on the thread pool; resume here on the UI sync context.
+            await SessionArchive.ExportNativeArchiveAsync(_all, path);
+            StatusText = $"Exported {_all.Count} sessions to {path}";
+        }
+        catch (Exception ex)
+        {
+            StatusText = "Export archive failed: " + Truncate(ex.Message, 160);
+        }
     }
 
     private async Task ExportSelectedArchiveAsync()
@@ -1933,8 +1941,15 @@ private async Task ExportSelectedArchiveAsync()
             return;
         }
 
-        await SessionArchive.ExportNativeArchiveAsync(sessions, path);
-        StatusText = $"Exported {sessions.Count} sessions to {path}";
+        try
+        {
+            await SessionArchive.ExportNativeArchiveAsync(sessions, path);
+            StatusText = $"Exported {sessions.Count} sessions to {path}";
+        }
+        catch (Exception ex)
+        {
+            StatusText = "Export archive failed: " + Truncate(ex.Message, 160);
+        }
     }
 
     private async Task ImportArchiveAsync()
@@ -1946,22 +1961,27 @@ private async Task ImportArchiveAsync()
             return;
         }
 
+        StatusText = "Importing archive…";
         try
         {
-            var imported = await SessionArchive.ImportNativeArchiveAsync(path);
-            foreach (var snap in imported)
+            // Off the UI sync context for zip IO so headless WaitUntil pumps cannot deadlock the import.
+            var imported = await SessionArchive.ImportNativeArchiveAsync(path).ConfigureAwait(false);
+            await MarshalToUiAsync(() =>
             {
-                _registry.Add(snap);
-                _all.Add(snap);
-            }
+                foreach (var snap in imported)
+                {
+                    _registry.Add(snap);
+                    _all.Add(snap);
+                }
 
-            ApplyFilter();
-            RefreshSessionCountText();
-            StatusText = $"Appended {imported.Count} sessions from {Path.GetFileName(path)}";
+                ApplyFilter();
+                RefreshSessionCountText();
+                StatusText = $"Appended {imported.Count} sessions from {Path.GetFileName(path)}";
+            });
         }
         catch (Exception ex)
         {
-            StatusText = "Import archive failed: " + Truncate(ex.Message, 160);
+            await MarshalToUiAsync(() => StatusText = "Import archive failed: " + Truncate(ex.Message, 160));
         }
     }
 
diff --git a/tests/Titanium.E2E.Tests/UiHeadless/AutomationIdCoverageHeadlessTests.cs b/tests/Titanium.E2E.Tests/UiHeadless/AutomationIdCoverageHeadlessTests.cs
index 8d944d22f..61338b6cb 100644
--- a/tests/Titanium.E2E.Tests/UiHeadless/AutomationIdCoverageHeadlessTests.cs
+++ b/tests/Titanium.E2E.Tests/UiHeadless/AutomationIdCoverageHeadlessTests.cs
@@ -275,21 +275,10 @@ await fx.DispatchAsync(() =>
             StringAssert.Contains(fx.ViewModel.StatusText, "Exported 1 sessions");
         });
 
-        // macOS runners can briefly keep the zip handle; wait until a shared read succeeds.
-        fx.PathPicker.OpenPath = zip;
-        var readableDeadline = DateTime.UtcNow.AddSeconds(10);
-        while (DateTime.UtcNow < readableDeadline)
-        {
-            try
-            {
-                await using var probe = new FileStream(zip, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
-                break;
-            }
-            catch (IOException)
-            {
-                await Task.Delay(50);
-            }
-        }
+        // Import from a copy so any lingering exclusive handle on the export path cannot block macOS.
+        var importZip = Path.Combine(Path.GetTempPath(), "twp-arch-in-" + Guid.NewGuid().ToString("N") + ".zip");
+        File.Copy(zip, importZip, overwrite: true);
+        fx.PathPicker.OpenPath = importZip;
 
         await fx.DispatchAsync(() => fx.Robot.Click("MenuImportArchive"));
 
@@ -300,9 +289,13 @@ await fx.WaitUntilAsync(
 
         await fx.DispatchAsync(() =>
         {
-            Assert.IsTrue(fx.PathPicker.OpenCalls >= 1);
-            StringAssert.Contains(fx.ViewModel.StatusText, "Appended");
+            Assert.IsTrue(fx.PathPicker.OpenCalls >= 1, "Import path picker was not invoked");
+            StringAssert.Contains(
+                fx.ViewModel.StatusText,
+                "Appended",
+                "StatusText after import: " + fx.ViewModel.StatusText);
         });
         try { File.Delete(zip); } catch { /* ignore */ }
+        try { File.Delete(importZip); } catch { /* ignore */ }
     }
 }