diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8a01124b..13e53176 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -273,6 +273,13 @@ All notable changes to vouch are documented here. Format follows
   in config.yaml (#476).
 
 ### Fixed
+- `sync_vault` catches the `ProposalError` that `propose_page` raises for a
+  deleted citation, not just `ArtifactNotFoundError`. a vault edit to a page
+  whose cited claim/entity/source was since removed hit propose_page's id
+  validation, which converts the miss to `ProposalError` — so the
+  `except ArtifactNotFoundError` handler never fired and the error escaped as
+  an uncaught traceback, bypassing the CLI's `except VaultSyncError` renderer.
+  it now surfaces as the intended one-line `VaultSyncError` (#547).
 - approve/reject/expire record the audit event *before* moving the
   proposal to decided/. a crash between the two used to leave a durable
   decision with no authoritative history; it now leaves a pending
diff --git a/src/vouch/vault_sync.py b/src/vouch/vault_sync.py
index d7a7f027..7ea9ffae 100644
--- a/src/vouch/vault_sync.py
+++ b/src/vouch/vault_sync.py
@@ -51,7 +51,7 @@
     ClaimStatus,
     PageStatus,
 )
-from .proposals import propose_page
+from .proposals import ProposalError, propose_page
 from .storage import (
     ArtifactNotFoundError,
     KBStore,
@@ -464,10 +464,16 @@ def sync_vault(
     if direction in {"forward", "both"}:
         try:
             r = vault_to_kb(store, vault_dir, actor=actor)
-        except ArtifactNotFoundError as e:
+        except (ArtifactNotFoundError, ProposalError) as e:
             # A vault edit referenced a claim/entity/source that no longer
             # exists in the KB. That's a *real* conflict the user has to
             # resolve in Obsidian, not a vouch bug; surface it cleanly.
+            # propose_page validates those ids and converts the miss to a
+            # ProposalError ("unknown claim/entity/source id"), not the raw
+            # ArtifactNotFoundError this used to catch — so the handler was
+            # dead and the ProposalError escaped as an uncaught traceback,
+            # bypassing the CLI's `except VaultSyncError` renderer. Catch
+            # both so it surfaces as the documented VaultSyncError.
             raise VaultSyncError(f"vault edit references unknown artifact: {e}") from e
         combined.pages_proposed.extend(r.pages_proposed)
         combined.pages_skipped_unchanged.extend(r.pages_skipped_unchanged)
diff --git a/tests/test_vault_sync.py b/tests/test_vault_sync.py
index b765b08c..fa15bb49 100644
--- a/tests/test_vault_sync.py
+++ b/tests/test_vault_sync.py
@@ -248,6 +248,27 @@ def test_sync_vault_rejects_missing_vault(store: KBStore, tmp_path: Path) -> Non
         sync_vault(store, tmp_path / "does-not-exist")
 
 
+def test_sync_vault_surfaces_deleted_citation_as_vault_sync_error(
+    store: KBStore, vault: Path,
+) -> None:
+    """A vault edit to a page whose cited claim was since deleted must
+    surface as a clean VaultSyncError, not the raw ProposalError that
+    propose_page raises for an unknown id — otherwise it escapes the dead
+    `except ArtifactNotFoundError` handler as an uncaught traceback,
+    bypassing the CLI's VaultSyncError renderer. Fixture cites `alpha-claim`."""
+    kb_to_vault(store, vault)
+    mirror = vault / VAULT_DIR / "pages" / "alpha-page.md"
+    mirror.write_text(
+        mirror.read_text(encoding="utf-8").replace("Original body.", "Edited."),
+        encoding="utf-8",
+    )
+    # Delete the cited claim so propose_page's id validation fails.
+    (store.kb_dir / "claims" / "alpha-claim.yaml").unlink()
+
+    with pytest.raises(VaultSyncError, match="unknown artifact"):
+        sync_vault(store, vault, direction="forward")
+
+
 # --- CLI surface ----------------------------------------------------------