diff --git a/nextcloud_mcp_server/vector/_errors.py b/nextcloud_mcp_server/vector/_errors.py
index 6e526317..f2cddc79 100644
--- a/nextcloud_mcp_server/vector/_errors.py
+++ b/nextcloud_mcp_server/vector/_errors.py
@@ -21,7 +21,8 @@ def format_exception_group(exc: BaseException) -> str:
     if not isinstance(exc, BaseExceptionGroup):
         return repr(exc)
     leaves = _flatten(exc)
-    return f"{len(leaves)} sub-exception(s): " + "; ".join(repr(e) for e in leaves)
+    noun = "sub-exception" if len(leaves) == 1 else "sub-exceptions"
+    return f"{len(leaves)} {noun}: " + "; ".join(repr(e) for e in leaves)
 
 
 def _flatten(exc: BaseException) -> list[BaseException]:
diff --git a/nextcloud_mcp_server/vector/oauth_sync.py b/nextcloud_mcp_server/vector/oauth_sync.py
index 6ce6b956..6cf44564 100644
--- a/nextcloud_mcp_server/vector/oauth_sync.py
+++ b/nextcloud_mcp_server/vector/oauth_sync.py
@@ -332,7 +332,7 @@ async def multi_user_processor_task(
             break
 
         except NotProvisionedError:
-            if doc_task:
+            if doc_task is not None:
                 logger.warning(
                     "[BasicAuth] User %s not provisioned, skipping %s_%s",
                     doc_task.user_id,
@@ -342,7 +342,7 @@ async def multi_user_processor_task(
             continue
 
         except Exception as e:
-            if doc_task:
+            if doc_task is not None:
                 logger.error(
                     "[BasicAuth] Processor %s error processing %s_%s: %s",
                     worker_id,
diff --git a/tests/unit/client/test_webdav.py b/tests/unit/client/test_webdav.py
index cf8a3871..ffa7c6f2 100644
--- a/tests/unit/client/test_webdav.py
+++ b/tests/unit/client/test_webdav.py
@@ -540,6 +540,15 @@ def test_webdav_path_encoding(path, expected):
     assert client._webdav_path(path) == expected
 
 
+@pytest.mark.unit
+def test_encode_dav_path_encodes_exactly_once():
+    """Pins the decoded-input precondition: a literal '%' becomes '%25', so an
+    already-encoded path passed in error would double-encode (caught here)."""
+    from nextcloud_mcp_server.client.webdav import _encode_dav_path
+
+    assert _encode_dav_path("already%20encoded.pdf") == "already%2520encoded.pdf"
+
+
 @pytest.mark.unit
 async def test_read_file_encodes_special_chars(mocker):
     """read_file must percent-encode '#', commas, and spaces in the path (card 309).
diff --git a/tests/unit/vector/test_errors.py b/tests/unit/vector/test_errors.py
index f3f7f0e4..8c5dfe22 100644
--- a/tests/unit/vector/test_errors.py
+++ b/tests/unit/vector/test_errors.py
@@ -41,4 +41,4 @@ def test_format_nested_exception_group_flattens_all_leaves():
     assert "ValueError" in formatted
     assert "ConnectError" in formatted
     assert "RuntimeError" in formatted
-    assert "3 sub-exception(s)" in formatted
+    assert "3 sub-exceptions" in formatted