diff --git a/backend/fluksio/flow/dashboards.py b/backend/fluksio/flow/dashboards.py
index 7286940..73dcf76 100644
--- a/backend/fluksio/flow/dashboards.py
+++ b/backend/fluksio/flow/dashboards.py
@@ -26,7 +26,13 @@ from pydantic import BaseModel, Field, field_validator, model_validator
 
 from fluksio.flow.messages import DType, qualify
 from fluksio.flow.schemas import FlowDef, _validate_name
-from fluksio.flow.store import FlowStore, StaleVersion, _updated_at, checked
+from fluksio.flow.store import (
+    FlowStore,
+    StaleVersion,
+    _updated_at,
+    checked,
+    copy_name,
+)
 
 #: Sibling of the shared-node library, and likewise not a flow.
 DASHBOARD_DIR = "_dashboards"
@@ -854,10 +860,7 @@ class DashboardStore:
         """
         with self._lock, self.flows._write_lock:
             source = self.read(name, draft=True)
-            new_name, count = f"{name}_copy", 1
-            while self.exists(new_name):
-                count += 1
-                new_name = f"{name}_copy_{count}"
+            new_name = copy_name(name, self.exists)
             copy = source.model_copy(
                 update={
                     "name": new_name,
diff --git a/backend/fluksio/flow/store.py b/backend/fluksio/flow/store.py
index f2ea6b2..e37de9e 100644
--- a/backend/fluksio/flow/store.py
+++ b/backend/fluksio/flow/store.py
@@ -16,10 +16,11 @@ from __future__ import annotations
 
 import json
 import logging
+import re
 import shutil
 import subprocess
 import threading
-from collections.abc import Iterable
+from collections.abc import Callable, Iterable
 from datetime import UTC, datetime
 from pathlib import Path
 
@@ -134,6 +135,16 @@ def _same_content(left: FlowDef, right: FlowDef) -> bool:
     )
 
 
+def copy_name(name: str, taken: Callable[[str], bool]) -> str:
+    """``{name}_copy``, then ``_copy_2`` and on, from a copy's own original."""
+    base = re.sub(r"_copy(_\d+)?$", "", name)
+    new_name, count = f"{base}_copy", 1
+    while taken(new_name):
+        count += 1
+        new_name = f"{base}_copy_{count}"
+    return new_name
+
+
 class FlowStore:
     """Reads and writes flows, committing every change."""
 
@@ -698,12 +709,9 @@ class FlowStore:
         """
         with self._write_lock:
             source = self.read_flow(name, draft=True)
-            new_name, count = f"{name}_copy", 1
             # The directory rather than `exists`: anything left in it would
             # otherwise end up in the copy.
-            while self._flow_dir(new_name).exists():
-                count += 1
-                new_name = f"{name}_copy_{count}"
+            new_name = copy_name(name, lambda n: self._flow_dir(n).exists())
 
             copy = source.model_copy(
                 update={
diff --git a/frontend/src/components/Common/OverviewToolbar.tsx b/frontend/src/components/Common/OverviewToolbar.tsx
index 9bfff7f..11be985 100644
--- a/frontend/src/components/Common/OverviewToolbar.tsx
+++ b/frontend/src/components/Common/OverviewToolbar.tsx
@@ -3,6 +3,7 @@ import { Check, Copy, Plus, Search, Trash2 } from "lucide-react"
 import { motion } from "motion/react"
 import { type ReactNode, useRef, useState } from "react"
 
+import type { ApiError } from "@/client"
 import { Button } from "@/components/ui/button"
 import {
   Dialog,
@@ -22,6 +23,7 @@ import {
 } from "@/components/ui/tooltip"
 import useCustomToast from "@/hooks/useCustomToast"
 import { transitions } from "@/lib/motion"
+import { extractErrorMessage } from "@/utils"
 
 /**
  * The bar over the flows and dashboards lists: find one, publish what is
@@ -233,8 +235,8 @@ function useBatch(
       for (const name of names) {
         try {
           await act(name)
-        } catch {
-          failed.push(name)
+        } catch (err) {
+          failed.push(`${name} (${extractErrorMessage(err as ApiError)})`)
         }
       }
       return failed