diff --git a/CHANGELOG.md b/CHANGELOG.md
index 668328c6..622d0a51 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,33 @@ Format follows [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ---
 
+## [1.19.3] — 2026-09-17
+
+> Bugfix-only release on the 1.19.0 stable line. Closes the root cause
+> behind #870, reproduced and confirmed on real Mac hardware.
+
+### Fixed
+
+- **macOS: `opensak.json` could be silently lost during the #825
+  migration instead of being moved (fixes #870)** — Reproducing the
+  original report on real Mac hardware showed that `shutil.move()` can
+  apparently fail for a specific file during the one-time macOS path
+  migration without ever raising an exception — evidenced by the
+  "migrated" `opensak.json` carrying the migration's own timestamp
+  rather than its original one, meaning it had been freshly created by
+  the app finding nothing at the destination, not actually moved.
+  Meanwhile other files in the very same migration run (e.g.
+  `Default.db`) moved correctly, ruling out a simple permissions
+  problem. The exact underlying trigger is still unconfirmed, but the
+  migration no longer depends on `shutil.move()` behaving correctly to
+  avoid data loss: each file is now copied, verified to match the
+  original by size, and only then is the source removed. If
+  verification ever fails, the original file is left completely
+  untouched (and the incomplete copy is cleaned up) instead of quietly
+  vanishing.
+
+---
+
 ## [1.19.2] — 2026-09-16
 
 > Bugfix-only release on the 1.19.0 stable line, following directly on
diff --git a/site/assets/screenshots/main-window.png b/site/assets/screenshots/main-window.png
index 2fe2f0c3..2a345f4f 100644
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diff --git a/site/assets/screenshots/map-maximized.png b/site/assets/screenshots/map-maximized.png
index f8f6f390..70b9460a 100644
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diff --git a/site/assets/screenshots/map-popout.png b/site/assets/screenshots/map-popout.png
index 040db706..a9e2f0ed 100644
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diff --git a/site/user-guide.html b/site/user-guide.html
index d31d68a5..ded317a0 100644
--- a/site/user-guide.html
+++ b/site/user-guide.html
@@ -3,7 +3,7 @@
 <head>
 <meta charset="UTF-8">
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
-<title>OpenSAK User Guide — v1.19.2</title>
+<title>OpenSAK User Guide — v1.19.3</title>
 <style>
   @import url('https://fonts.googleapis.com/css2?family=Playfair+Display:wght@700&family=Source+Serif+4:ital,wght@0,300;0,400;0,600;1,400&family=JetBrains+Mono:wght@400;500&display=swap');
 
@@ -473,7 +473,7 @@
 <nav>
   <div class="nav-header">
     <span class="nav-logo">OpenSAK</span>
-    <div class="nav-version">User Guide · v1.19.2</div>
+    <div class="nav-version">User Guide · v1.19.3</div>
   </div>
 
   <div class="nav-section-heading">Getting Started</div>
@@ -535,7 +535,7 @@
     <div class="hero-eyebrow">Complete User Guide</div>
     <h1>OpenSAK</h1>
     <p class="hero-sub">The open-source geocache management tool for Windows, Linux, and macOS.</p>
-    <div class="hero-meta">Version 1.19.2 &nbsp;·&nbsp; MIT Licence &nbsp;·&nbsp; <a href="https://github.com/OpenSAK-Org/opensak">github.com/OpenSAK-Org/opensak</a></div>
+    <div class="hero-meta">Version 1.19.3 &nbsp;·&nbsp; MIT Licence &nbsp;·&nbsp; <a href="https://github.com/OpenSAK-Org/opensak">github.com/OpenSAK-Org/opensak</a></div>
   </div>
 
   <figure class="screenshot" style="margin-top:-0.5rem;">
@@ -1463,7 +1463,7 @@ <h3>Debug Log</h3>
         <tr><td>Bug reports &amp; feature requests</td><td><a href="https://github.com/OpenSAK-Org/opensak/issues">github.com/OpenSAK-Org/opensak/issues</a></td></tr>
         <tr><td>Community discussion</td><td><a href="https://www.facebook.com/groups/opensak">Facebook group: OpenSAK</a></td></tr>
         <tr><td>Releases &amp; downloads</td><td><a href="https://github.com/OpenSAK-Org/opensak/releases">github.com/OpenSAK-Org/opensak/releases</a></td></tr>
-        <tr><td>Changelog</td><td><a href="https://github.com/OpenSAK-Org/opensak/blob/v1.19.2/CHANGELOG.md">CHANGELOG.md on GitHub</a></td></tr>
+        <tr><td>Changelog</td><td><a href="https://github.com/OpenSAK-Org/opensak/blob/v1.19.3/CHANGELOG.md">CHANGELOG.md on GitHub</a></td></tr>
         <tr><td>Contributing</td><td><a href="https://github.com/OpenSAK-Org/opensak/blob/main/CONTRIBUTING.md">CONTRIBUTING.md on GitHub</a></td></tr>
         <tr><td>Support the project</td><td><a href="https://opencollective.com/opensak">opencollective.com/opensak</a></td></tr>
         <tr><td>Website</td><td><a href="https://opensak.com">opensak.com</a></td></tr>
@@ -1473,7 +1473,7 @@ <h3>Debug Log</h3>
     <div class="callout tip"><div class="callout-icon">💡</div><div>OpenSAK is free and open-source software released under the MIT licence. Contributions of any kind — code, translations, documentation, or testing — are very welcome.</div></div>
 
     <p style="margin-top:2rem;color:var(--ink-light);font-size:0.85rem;font-style:italic;">
-      This guide was generated from the OpenSAK source code (v1.19.2). Last updated August 2026.
+      This guide was generated from the OpenSAK source code (v1.19.3). Last updated August 2026.
     </p>
   </section>
 
diff --git a/src/opensak/__init__.py b/src/opensak/__init__.py
index b82cd94f..196fb20b 100644
--- a/src/opensak/__init__.py
+++ b/src/opensak/__init__.py
@@ -1,4 +1,4 @@
 """OpenSAK — cross-platform geocache management tool."""
-__version__ = "1.19.2"
+__version__ = "1.19.3"
 __author__ = "OpenSAK Contributors"
 __license__ = "MIT"
diff --git a/src/opensak/settings_store.py b/src/opensak/settings_store.py
index 02a16857..0f59edd0 100644
--- a/src/opensak/settings_store.py
+++ b/src/opensak/settings_store.py
@@ -607,6 +607,87 @@ def _backup_opensak_json_in_place(source_dir: Path) -> None:
                     source, exc)
 
 
+def _move_verified(entry: Path, target: Path) -> bool:
+    """
+    Robust erstatning for shutil.move() til brug i
+    migrate_macos_default_paths(): kopiér, verificér at kopien reelt
+    matcher kilden, og slet FØRST kildefilen når det er bekræftet.
+
+    Issue #870: reproduceret på rigtig Mac-hardware, at shutil.move()
+    tilsyneladende kan fejle stille for netop opensak.json under denne
+    migrering, mens andre filer i samme løkke (fx Default.db) flyttes
+    korrekt — uden at nogen exception nogensinde ramte den daværende
+    except-gren. Timestamp-bevis: den "migrerede" opensak.json havde
+    migreringstidspunktet som mtime, ikke det oprindelige, bekræftende
+    at filen blev nyoprettet af SettingsStore (fordi intet fandtes på
+    destinationen), ikke flyttet.
+
+    Den præcise bagvedliggende årsag (race condition, macOS-specifik
+    I/O-kvirk, andet) er stadig ukendt — denne funktion løser symptomet
+    uafhængigt af årsagen: kildefilen fjernes ALDRIG, medmindre
+    destinationen beviseligt indeholder identisk indhold bagefter.
+    Undlader bevidst en indholds-hash for at holde det billigt for store
+    databasefiler — filstørrelse er tilstrækkeligt til at opdage den
+    "tom/delvis fil" fejlklasse, vi faktisk har observeret.
+
+    Kataloger (bør ikke forekomme i praksis i denne installations-mappe,
+    men for en sikkerheds skyld) falder tilbage til almindelig
+    shutil.move(), da størrelses-verifikation ikke giver mening for dem.
+
+    Returnerer True hvis flytningen lykkedes og blev verificeret.
+    """
+    if entry.is_dir():
+        try:
+            shutil.move(str(entry), str(target))
+            return True
+        except OSError as exc:
+            _log.warning("migrate_macos_default_paths: flytning af mappen "
+                          "%s -> %s fejlede: %s", entry, target, exc)
+            return False
+
+    try:
+        shutil.copy2(str(entry), str(target))
+    except OSError as exc:
+        _log.warning("migrate_macos_default_paths: kopiering af %s -> %s "
+                      "fejlede: %s", entry, target, exc)
+        return False
+
+    try:
+        source_size = entry.stat().st_size
+        target_size = target.stat().st_size
+    except OSError as exc:
+        _log.warning("migrate_macos_default_paths: kunne ikke verificere "
+                      "%s efter kopiering fra %s: %s", target, entry, exc)
+        return False
+
+    if source_size != target_size:
+        _log.warning(
+            "migrate_macos_default_paths: verifikation fejlede for %s -> "
+            "%s (kilde=%d bytes, kopi=%d bytes) — kildefilen BEVARES "
+            "urørt, kopien slettes igen", entry, target, source_size,
+            target_size,
+        )
+        try:
+            target.unlink()
+        except OSError:
+            pass
+        return False
+
+    try:
+        entry.unlink()
+    except OSError as exc:
+        # Kopien er verificeret identisk, men kilden kunne ikke fjernes
+        # (fx en fil der er låst). Ufarligt at have begge liggende —
+        # betragt selve migreringen af DENNE fil som lykkedes.
+        _log.warning(
+            "migrate_macos_default_paths: kunne ikke slette kildefilen %s "
+            "efter bekræftet kopiering til %s: %s (begge steder har nu "
+            "identisk indhold — ufarligt, men ryd op manuelt om ønsket)",
+            entry, target, exc,
+        )
+    return True
+
+
 def migrate_macos_default_paths() -> bool:
     """
     Én-gangs migration af eksisterende macOS-brugeres data fra den
@@ -703,16 +784,15 @@ def migrate_macos_default_paths() -> bool:
                     _log.debug("migrate_macos_default_paths: kollision på %s "
                                 "— springer over, rører intet", target)
                     continue  # kollision — rør det ikke, behold begge som de er
-                try:
-                    shutil.move(str(entry), str(target))
+                if _move_verified(entry, target):
                     migrated_something = True
-                    _log.debug("migrate_macos_default_paths: flyttede %s -> %s",
-                                entry, target)
-                except OSError as exc:
-                    print(f"[settings] macOS-migration: kunne ikke flytte "
-                          f"{entry} → {target}: {exc}")
+                    _log.debug("migrate_macos_default_paths: flyttede %s -> %s "
+                                "(verificeret)", entry, target)
+                else:
                     _log.debug("migrate_macos_default_paths: flytning af %s "
-                                "-> %s fejlede: %s", entry, target, exc)
+                                "-> %s fejlede eller kunne ikke verificeres "
+                                "(se warning ovenfor) — kildefil bevaret",
+                                entry, target)
             try:
                 if not any(old_default_install.iterdir()):
                     old_default_install.rmdir()
diff --git a/tests/unit-tests/test_settings_store.py b/tests/unit-tests/test_settings_store.py
index 74e32235..db0423ee 100644
--- a/tests/unit-tests/test_settings_store.py
+++ b/tests/unit-tests/test_settings_store.py
@@ -669,6 +669,148 @@ def test_rewrite_helper_invalid_json_is_safe(self, tmp_path):
         ss._rewrite_stale_install_dir_paths(bad, tmp_path / "old", tmp_path / "new")
         assert bad.read_text(encoding="utf-8") == "{not valid json"  # left untouched
 
+    @posix_only
+    def test_end_to_end_survives_silent_copy_corruption_of_settings(
+        self, monkeypatch, tmp_path
+    ):
+        """
+        Full-migration regression test for #870: simulates the exact
+        symptom reproduced on real hardware — copying opensak.json
+        "succeeds" with no exception, but the destination ends up empty
+        instead of matching the source (Default.db, in the same run,
+        copies correctly). Before the _move_verified() fix, this meant
+        the real settings were silently lost, and the app fell back to
+        a fresh-looking install (missing username/home location) on
+        next launch. After the fix, the real opensak.json must survive
+        in the OLD directory rather than being replaced by an empty one.
+        """
+        self._patch_platform(monkeypatch, tmp_path)
+        old_dir = ss._legacy_macos_default_install_dir()
+        old_dir.mkdir(parents=True)
+        real_settings = json.dumps({"user.gc_username": "Allan", "user.home_lat": 55.6})
+        (old_dir / "opensak.json").write_text(real_settings, encoding="utf-8")
+        (old_dir / "Default.db").write_text("real-cache-data", encoding="utf-8")
+
+        original_copy2 = ss.shutil.copy2
+
+        def _corrupt_only_settings_json(src, dst, *a, **kw):
+            if Path(src).name == "opensak.json":
+                Path(dst).write_text("{}", encoding="utf-8")  # silent corruption
+            else:
+                original_copy2(src, dst, *a, **kw)  # everything else moves fine
+        monkeypatch.setattr(ss.shutil, "copy2", _corrupt_only_settings_json)
+
+        ss.migrate_macos_default_paths()
+
+        new_dir = ss._default_install_dir()
+        # The database migrated fine, same as the real hardware reproduction.
+        assert (new_dir / "Default.db").read_text(encoding="utf-8") == "real-cache-data"
+        # The settings file must NOT have been silently replaced by an
+        # empty one — the real data must still be found, in the old dir,
+        # not lost.
+        assert not (new_dir / "opensak.json").exists()
+        assert (old_dir / "opensak.json").read_text(encoding="utf-8") == real_settings
+
+
+class TestMoveVerified:
+    """
+    Issue #870: reproduced on real Mac hardware that shutil.move() can
+    apparently fail silently for a specific file during the macOS #825
+    migration, with no exception ever raised — evidenced by a "migrated"
+    opensak.json carrying the migration run's own timestamp instead of
+    its original one, meaning it was freshly created (nothing found at
+    the destination), not actually moved.
+
+    _move_verified() replaces the raw shutil.move() call with a
+    copy-then-verify-then-delete sequence, so the source file is never
+    lost regardless of the still-unconfirmed underlying cause.
+    """
+
+    def test_successful_move_copies_content_and_removes_source(self, tmp_path):
+        entry = tmp_path / "opensak.json"
+        entry.write_text('{"real": "data"}', encoding="utf-8")
+        target = tmp_path / "dest" / "opensak.json"
+        target.parent.mkdir()
+
+        assert ss._move_verified(entry, target) is True
+        assert not entry.exists()
+        assert target.read_text(encoding="utf-8") == '{"real": "data"}'
+
+    def test_directory_falls_back_to_plain_move(self, tmp_path):
+        entry = tmp_path / "somedir"
+        entry.mkdir()
+        (entry / "inner.txt").write_text("x", encoding="utf-8")
+        target = tmp_path / "dest" / "somedir"
+        target.parent.mkdir()
+
+        assert ss._move_verified(entry, target) is True
+        assert not entry.exists()
+        assert (target / "inner.txt").read_text(encoding="utf-8") == "x"
+
+    def test_copy_failure_preserves_source(self, monkeypatch, tmp_path):
+        entry = tmp_path / "opensak.json"
+        entry.write_text('{"real": "data"}', encoding="utf-8")
+        target = tmp_path / "dest" / "opensak.json"
+        target.parent.mkdir()
+
+        def _boom(*a, **kw):
+            raise OSError("simulated I/O failure")
+        monkeypatch.setattr(ss.shutil, "copy2", _boom)
+
+        assert ss._move_verified(entry, target) is False
+        # Source must survive untouched — this is the core guarantee.
+        assert entry.read_text(encoding="utf-8") == '{"real": "data"}'
+        assert not target.exists()
+
+    def test_size_mismatch_preserves_source_and_cleans_up_partial_copy(
+        self, monkeypatch, tmp_path
+    ):
+        """
+        Directly reproduces the observed #870 symptom: the copy
+        "succeeds" (no exception) but the destination doesn't actually
+        match the source — e.g. an empty/truncated file appears there
+        instead. Must be treated as a failed move, not a successful one.
+        """
+        entry = tmp_path / "opensak.json"
+        entry.write_text('{"user.gc_username": "MikeWood"}', encoding="utf-8")
+        target = tmp_path / "dest" / "opensak.json"
+        target.parent.mkdir()
+
+        def _write_empty_instead(src, dst, *a, **kw):
+            Path(dst).write_text("{}", encoding="utf-8")
+        monkeypatch.setattr(ss.shutil, "copy2", _write_empty_instead)
+
+        assert ss._move_verified(entry, target) is False
+        # Source must survive untouched — this is the whole point of the fix.
+        assert entry.read_text(encoding="utf-8") == '{"user.gc_username": "MikeWood"}'
+        # The bogus partial copy must be cleaned up, not left behind
+        # looking like a (wrong) successful migration.
+        assert not target.exists()
+
+    def test_source_unlink_failure_still_counts_as_success(self, monkeypatch, tmp_path):
+        """
+        If the verified-identical copy exists but the source can't be
+        deleted (e.g. a locked file), the migration of THIS file should
+        still be considered successful — having both is harmless, unlike
+        losing the data.
+        """
+        entry = tmp_path / "opensak.json"
+        entry.write_text('{"real": "data"}', encoding="utf-8")
+        target = tmp_path / "dest" / "opensak.json"
+        target.parent.mkdir()
+
+        original_unlink = Path.unlink
+
+        def _boom_unlink(self, *a, **kw):
+            if self == entry:
+                raise OSError("simulated: file locked")
+            return original_unlink(self, *a, **kw)
+        monkeypatch.setattr(Path, "unlink", _boom_unlink)
+
+        assert ss._move_verified(entry, target) is True
+        assert entry.exists()  # left behind, but harmless
+        assert target.read_text(encoding="utf-8") == '{"real": "data"}'
+
 
 class TestBackupOpensakJsonInPlace:
     """
