diff --git a/CHANGELOG.md b/CHANGELOG.md
index bf757e8..97c4c24 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,14 @@
 # Änderungsprotokoll
 
+## 1.0.12 – 2026-09-27
+
+### Behoben
+
+- **Endlosschleife bei Wiederholungen beseitigt:** Aufgaben in Wiederholungsschleifen werden nach dem Einreihen sauber aus der Retry-Warteliste entfernt und bei reinen Fehlern ohne gesperrte Dateien nicht mehr dauerhaft im 10-Sekunden-Takt neu gestartet.
+- **Wiederholungs-Backoff und Versuchslimit:** Für gesperrte Dateien greift ein exponentielles Backoff (30s, 60s, 120s bis max. 300s) sowie ein Limit von 5 automatischen Versuchen, um Festplatte, Netzwerk und Prozessor vor unnötigen Dauerläufen zu schützen.
+- **Flüchtige Cache-Dateien ohne Fehlermeldung:** Dateien, die zwischen Inventarerstellung und Kopiervorgang gelöscht wurden (z. B. dynamische Browser- oder Anwendungs-Caches), werden sauber als übersprungen gewertet und brechen die Sicherung nicht mehr mit `[WinError 2]` ab.
+- **Kein Einfrieren der Benutzeroberfläche:** Das automatische Weiterscrollen der Protokolltabelle bei vielen gleichzeitigen Meldungen wird gebündelt entprellt, die Abfrage des Windows Restart Managers für gesperrte Ordner wird pro Verzeichnis zwischengespeichert und Fortschrittsmeldungen werden im GUI-Thread gedrosselt.
+
 ## 1.0.11 – 2026-09-27
 
 ### Behoben
diff --git a/pyproject.toml b/pyproject.toml
index 6d7359f..dad07a1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "syncvito"
-version = "1.0.11"
+version = "1.0.12"
 description = "Windows-Desktopwerkzeug für lokale und NAS-Synchronisation"
 readme = "README.md"
 requires-python = ">=3.11"
diff --git a/src/syncvito/coordinator.py b/src/syncvito/coordinator.py
index cda8176..27fc9a9 100644
--- a/src/syncvito/coordinator.py
+++ b/src/syncvito/coordinator.py
@@ -88,6 +88,8 @@ class SyncCoordinator(QObject):
         self._queue: deque[str] = deque()
         self._running_task_id: str | None = None
         self._retry_tasks: dict[str, list[Path]] = {}
+        self._retry_attempts: dict[str, int] = {}
+        self._retry_cooldowns: dict[str, datetime] = {}
         self._lock_messages: dict[str, str] = {}
         self._task_states: dict[str, TaskRuntimeState] = {
             task.id: TaskRuntimeState.ACTIVE if task.enabled else TaskRuntimeState.PAUSED for task in config.tasks
@@ -142,6 +144,8 @@ class SyncCoordinator(QObject):
         known_ids = {task.id for task in self.config.tasks}
         self._task_states = {task_id: state for task_id, state in self._task_states.items() if task_id in known_ids}
         self._retry_tasks = {task_id: paths for task_id, paths in self._retry_tasks.items() if task_id in known_ids}
+        self._retry_attempts = {task_id: att for task_id, att in self._retry_attempts.items() if task_id in known_ids}
+        self._retry_cooldowns = {task_id: cd for task_id, cd in self._retry_cooldowns.items() if task_id in known_ids}
         self._lock_messages = {
             task_id: message for task_id, message in self._lock_messages.items() if task_id in known_ids
         }
@@ -152,6 +156,8 @@ class SyncCoordinator(QObject):
                 self._set_task_state(task.id, desired)
             if not task.enabled:
                 self._retry_tasks.pop(task.id, None)
+                self._retry_attempts.pop(task.id, None)
+                self._retry_cooldowns.pop(task.id, None)
                 self._lock_messages.pop(task.id, None)
         enabled_ids = {task.id for task in self.config.tasks if task.enabled}
         self._queue = deque(task_id for task_id in self._queue if task_id in enabled_ids)
@@ -179,6 +185,8 @@ class SyncCoordinator(QObject):
         task = self._task(task_id)
         if task is None or not task.enabled:
             return
+        self._retry_attempts.pop(task_id, None)
+        self._retry_cooldowns.pop(task_id, None)
         if self.config.settings.paused:
             if task_id != self._running_task_id and task_id not in self._queue:
                 self._queue.append(task_id)
@@ -229,7 +237,9 @@ class SyncCoordinator(QObject):
         """Aktualisiert alle Dateisystemüberwachungen."""
         errors = self.monitor.rebuild(self.config.tasks)
         for task_id, message in errors:
-            self._retry_tasks[task_id] = []
+            self._retry_tasks.pop(task_id, None)
+            self._retry_attempts.pop(task_id, None)
+            self._retry_cooldowns.pop(task_id, None)
             self._set_task_state(task_id, TaskRuntimeState.ERROR)
             self.log_created.emit("Echtzeit", "Fehler", message)
         self._emit_overall_status()
@@ -315,12 +325,17 @@ class SyncCoordinator(QObject):
             self._emit_lock_summary()
         if result.errors:
             # Auch zusätzliche Fehler eines teilweise blockierten Laufs sichtbar halten.
-            self._retry_tasks[task_id] = []
+            if not result.blocked:
+                self._retry_tasks.pop(task_id, None)
+                self._retry_attempts.pop(task_id, None)
+                self._retry_cooldowns.pop(task_id, None)
             for error in result.errors:
                 self.log_created.emit(task.name, "Fehler", error)
             self._set_task_state(task_id, TaskRuntimeState.ERROR)
         elif not result.blocked:
             self._retry_tasks.pop(task_id, None)
+            self._retry_attempts.pop(task_id, None)
+            self._retry_cooldowns.pop(task_id, None)
             summary = f"{result.copied} kopiert, {result.deleted} gelöscht, {result.conflicts} Konfliktkopien"
             self.log_created.emit(task.name, "Erfolg", summary)
             self._set_task_state(task_id, TaskRuntimeState.ACTIVE)
@@ -329,7 +344,9 @@ class SyncCoordinator(QObject):
     def _on_failed(self, task_id: str, detail: str, inaccessible: bool) -> None:
         task = self._task(task_id)
         name = task.name if task else "Aufgabe"
-        self._retry_tasks[task_id] = []
+        self._retry_tasks.pop(task_id, None)
+        self._retry_attempts.pop(task_id, None)
+        self._retry_cooldowns.pop(task_id, None)
         self._lock_messages.pop(task_id, None)
         self._emit_lock_summary()
         self._set_task_state(task_id, TaskRuntimeState.ERROR)
@@ -372,9 +389,36 @@ class SyncCoordinator(QObject):
     def _check_retries(self) -> None:
         if self.config.settings.paused or self.is_running:
             return
+        now = datetime.now()
+        ready_tasks: list[str] = []
         for task_id, paths in list(self._retry_tasks.items()):
-            if paths and all(is_file_locked(path) for path in paths):
+            cooldown_until = self._retry_cooldowns.get(task_id)
+            if cooldown_until and now < cooldown_until:
                 continue
+            attempts = self._retry_attempts.get(task_id, 0)
+            if attempts >= 5:
+                if attempts == 5:
+                    task = self._task(task_id)
+                    name = task.name if task else task_id
+                    self.log_created.emit(
+                        name,
+                        "Hinweis",
+                        "Automatische Wiederholungen vorübergehend ausgesetzt. Bitte sperrende Programme schließen.",
+                    )
+                    self._retry_attempts[task_id] = attempts + 1
+                continue
+
+            check_paths = paths[:10] if len(paths) > 10 else paths
+            if paths and all(is_file_locked(path) for path in check_paths):
+                continue
+            ready_tasks.append(task_id)
+
+        for task_id in ready_tasks:
+            self._retry_tasks.pop(task_id, None)
+            attempts = self._retry_attempts.get(task_id, 0) + 1
+            self._retry_attempts[task_id] = attempts
+            backoff_seconds = min(300, 30 * (2 ** min(attempts - 1, 4)))
+            self._retry_cooldowns[task_id] = now + timedelta(seconds=backoff_seconds)
             self.log_created.emit(
                 "Automatischer Versuch", "Hinweis", "Blockierte oder nicht erreichbare Datei wird erneut geprüft."
             )
diff --git a/src/syncvito/main_window.py b/src/syncvito/main_window.py
index 0d0ad90..74dabaf 100644
--- a/src/syncvito/main_window.py
+++ b/src/syncvito/main_window.py
@@ -803,6 +803,15 @@ class MainWindow(QMainWindow):
             self.log_table.setItem(row, column, item)
         if self.log_table.rowCount() > 1000:
             self.log_table.removeRow(0)
+        self._schedule_log_scroll()
+
+    def _schedule_log_scroll(self) -> None:
+        if not getattr(self, "_log_scroll_pending", False):
+            self._log_scroll_pending = True
+            QTimer.singleShot(50, self._do_scroll_log)
+
+    def _do_scroll_log(self) -> None:
+        self._log_scroll_pending = False
         self.log_table.scrollToBottom()
 
     def _set_global_status(self, status: str, text: str) -> None:
diff --git a/src/syncvito/sync_engine.py b/src/syncvito/sync_engine.py
index a3678d3..78f7fee 100644
--- a/src/syncvito/sync_engine.py
+++ b/src/syncvito/sync_engine.py
@@ -141,6 +141,11 @@ class SyncEngine:
             if stage_name not in stages:
                 stages.append(stage_name)
 
+        known_locking_processes: dict[Path, tuple[LockingProcess, ...]] = {}
+        rm_query_count = 0
+        last_progress_time = 0.0
+        current_stage = ""
+
         if progress:
             progress(0, "Änderungen werden vorbereitet …")
         for index, operation in enumerate(operations, start=1):
@@ -154,6 +159,9 @@ class SyncEngine:
             try:
                 self._execute(operation, result)
             except (OSError, shutil.Error) as exc:
+                if isinstance(exc, FileNotFoundError) and operation.source and not operation.source.exists():
+                    result.skipped += 1
+                    continue
                 failed_path = (
                     Path(exc.filename2 or exc.filename)
                     if isinstance(exc, OSError) and (exc.filename2 or exc.filename)
@@ -161,13 +169,28 @@ class SyncEngine:
                 )
                 blocked_path = _blocked_path(operation, exc)
                 if blocked_path is not None:
-                    processes = tuple(find_locking_processes(blocked_path))
+                    parent_dir = blocked_path.parent
+                    if parent_dir in known_locking_processes:
+                        processes = known_locking_processes[parent_dir]
+                    elif rm_query_count < 10:
+                        discovered = tuple(find_locking_processes(blocked_path))
+                        rm_query_count += 1
+                        if discovered:
+                            known_locking_processes[parent_dir] = discovered
+                        processes = discovered
+                    else:
+                        processes = next(iter(known_locking_processes.values()), ())
                     result.blocked.append(BlockedFile(blocked_path, processes))
                 elif isinstance(exc, PermissionError):
                     result.errors.append(f"Zugriff verweigert: {failed_path} ({exc})")
                 else:
                     result.errors.append(f"{failed_path}: {exc}")
-            if progress:
+            now = monotonic()
+            is_last = index == total
+            stage_changed = stage != current_stage
+            if progress and (is_last or stage_changed or now - last_progress_time >= 0.05):
+                last_progress_time = now
+                current_stage = stage
                 if len(stages) > 1:
                     stage_idx = stages.index(stage) + 1
                     detail = f"[{stage_idx}/{len(stages)} {stage}] {operation.kind}: {operation.relative}"
@@ -344,6 +367,9 @@ class SyncEngine:
             return
         if operation.source is None:
             return
+        if not operation.source.exists():
+            result.skipped += 1
+            return
         operation.target.parent.mkdir(parents=True, exist_ok=True)
         if operation.conflict_copy and operation.target.exists():
             conflict_path = _conflict_path(operation.target)
diff --git a/tests/test_coordinator.py b/tests/test_coordinator.py
index bb809aa..9a3e62a 100644
--- a/tests/test_coordinator.py
+++ b/tests/test_coordinator.py
@@ -73,6 +73,30 @@ def test_retry_queues_all_ready_tasks(coordinator: SyncCoordinator, monkeypatch:
     monkeypatch.setattr(coordinator, "enqueue", queued.append)
     coordinator._check_retries()
     assert queued == ["first", "second"]
+    assert "first" not in coordinator._retry_tasks
+    assert "second" not in coordinator._retry_tasks
+
+
+def test_task_with_only_errors_is_not_queued_for_auto_retry(
+    coordinator: SyncCoordinator, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    task = coordinator.config.tasks[0]
+    coordinator._on_finished(task.id, SyncResult(errors=["Zugriff verweigert"]))
+    assert task.id not in coordinator._retry_tasks
+    queued = []
+    monkeypatch.setattr(coordinator, "enqueue", queued.append)
+    coordinator._check_retries()
+    assert queued == []
+
+
+def test_retry_max_attempts_cap(coordinator: SyncCoordinator, monkeypatch: pytest.MonkeyPatch) -> None:
+    task = coordinator.config.tasks[0]
+    coordinator._retry_tasks[task.id] = []
+    coordinator._retry_attempts[task.id] = 5
+    queued = []
+    monkeypatch.setattr(coordinator, "enqueue", queued.append)
+    coordinator._check_retries()
+    assert queued == []
 
 
 def test_start_resets_stale_progress_before_worker_starts(
diff --git a/tests/test_sync_engine.py b/tests/test_sync_engine.py
index f18d9a3..0b55222 100644
--- a/tests/test_sync_engine.py
+++ b/tests/test_sync_engine.py
@@ -269,3 +269,27 @@ def test_pause_and_resume_continues_where_interrupted(tmp_path: Path) -> None:
     assert (target / "a.txt").exists()
     assert (target / "b.txt").exists()
     assert (target / "c.txt").exists()
+
+
+def test_concurrently_deleted_source_file_is_skipped(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
+    source = tmp_path / "source"
+    target = tmp_path / "target"
+    source.mkdir()
+    target.mkdir()
+    (source / "ephemeral.txt").write_text("wird gelöscht")
+    task = SyncTask(name="Transient", source=str(source), target=str(target))
+    engine = _engine(tmp_path)
+
+    # Simuliere, dass die Datei kurz vor der Ausführung gelöscht wurde
+    def delete_before_execute(operation, result):
+        if operation.source and operation.source.name == "ephemeral.txt":
+            operation.source.unlink(missing_ok=True)
+        return SyncEngine._execute(operation, result)
+
+    monkeypatch.setattr(engine, "_execute", delete_before_execute)
+    result = engine.synchronize(task)
+
+    assert result.successful
+    assert result.skipped == 1
+    assert not result.errors
+    assert not (target / "ephemeral.txt").exists()
diff --git a/version.txt b/version.txt
index 59e9e60..bb83058 100644
--- a/version.txt
+++ b/version.txt
@@ -1 +1 @@
-1.0.11
+1.0.12