diff --git a/core/downloads/post_processing.py b/core/downloads/post_processing.py
index 5dbbae97..2be79eba 100644
--- a/core/downloads/post_processing.py
+++ b/core/downloads/post_processing.py
@@ -453,7 +453,19 @@ def run_post_processing_worker(task_id: str, batch_id: str, deps: PostProcessDep
                         logger.error(f"[Post-Processing] Task {task_id} was completed by stream processor - not marking as failed")
                         return
                     download_tasks[task_id]['status'] = 'failed'
-                    download_tasks[task_id]['error_message'] = f'File not found on disk after {_file_search_max_retries} search attempts. Expected: {os.path.basename(task_filename)}'
+                    # slskd reported the transfer complete, but the finder never located
+                    # the file under the configured download folder. Name the folder we
+                    # searched and the two real causes — "still being written" (timing)
+                    # or "SoulSync's download path doesn't match slskd's" (the classic
+                    # standalone config mismatch) — so the user can self-diagnose instead
+                    # of getting an opaque "not found". (Discord: Shdjfgatdif.)
+                    _searched_name = os.path.basename((task_filename or '').replace('\\', '/')) or task_filename
+                    download_tasks[task_id]['error_message'] = (
+                        f"slskd reported '{_searched_name}' downloaded, but it never appeared "
+                        f"under the download folder ({download_dir}) after {_file_search_max_retries} "
+                        f"checks. Either it's still being written, or SoulSync's download path "
+                        f"doesn't match slskd's download directory — they must point at the same folder."
+                    )
             deps.on_download_completed(batch_id, task_id, False)
             return
 
diff --git a/tests/downloads/test_downloads_post_processing.py b/tests/downloads/test_downloads_post_processing.py
index 701c6e2b..c8ca26b4 100644
--- a/tests/downloads/test_downloads_post_processing.py
+++ b/tests/downloads/test_downloads_post_processing.py
@@ -170,7 +170,12 @@ def test_file_not_found_after_retries_marks_failed(monkeypatch):
     deps, rec = _build_deps()
     pp.run_post_processing_worker('t1', 'b1', deps)
     assert download_tasks['t1']['status'] == 'failed'
-    assert 'File not found on disk' in download_tasks['t1']['error_message']
+    # Actionable failure: names the folder searched + the two real causes, so a
+    # standalone user with a path mismatch can self-diagnose (Discord: Shdjfgatdif).
+    msg = download_tasks['t1']['error_message']
+    assert './downloads' in msg                    # the folder we actually searched
+    assert "download path doesn't match slskd" in msg   # the config-mismatch hint
+    assert 'song.flac' in msg                       # the file slskd reported
     assert ('on_complete', ('b1', 't1', False), {}) in rec.calls