first working version

lib/widgets/active_block_dialog.dart

@@ -0,0 +1,54 @@
+import 'package:flutter/material.dart';
+import '../services/localization_service.dart';
+
+/// Dialog shown whenever a check finds that the user's OSM account has an
+/// active block. Unlike the unread-notifications dialog, this has no
+/// "don't show again" option and is shown every time a check finds a block.
+class ActiveBlockDialog extends StatelessWidget {
+  final VoidCallback onViewMessages;
+  final VoidCallback onDismiss;
+
+  const ActiveBlockDialog({
+    super.key,
+    required this.onViewMessages,
+    required this.onDismiss,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final locService = LocalizationService.instance;
+
+    return AlertDialog(
+      title: Row(
+        children: [
+          Icon(
+            Icons.block,
+            color: Theme.of(context).colorScheme.error,
+          ),
+          const SizedBox(width: 8),
+          Expanded(
+            child: Text(locService.t('auth.activeBlockTitle')),
+          ),
+        ],
+      ),
+      content: Text(locService.t('auth.activeBlockMessage')),
+      actions: [
+        TextButton(
+          onPressed: () {
+            Navigator.of(context).pop();
+            onDismiss();
+          },
+          child: Text(locService.t('actions.dismiss')),
+        ),
+        FilledButton.icon(
+          onPressed: () {
+            Navigator.of(context).pop();
+            onViewMessages();
+          },
+          icon: const Icon(Icons.message, size: 18),
+          label: Text(locService.t('auth.viewMessages')),
+        ),
+      ],
+    );
+  }
+}

lib/widgets/add_node_sheet.dart

@@ -421,6 +421,7 @@ class _AddNodeSheetState extends State<AddNodeSheet> {
         }
         
         final allowSubmit = appState.isLoggedIn && 
+            !appState.hasActiveBlock &&
             submittableProfiles.isNotEmpty && 
             session.profile != null && 
             session.profile!.isSubmittable &&
@@ -493,6 +494,22 @@ class _AddNodeSheetState extends State<AddNodeSheet> {
                     ],
                   ),
                 )
+              else if (appState.hasActiveBlock)
+                Padding(
+                  padding: const EdgeInsets.fromLTRB(16, 0, 16, 12),
+                  child: Row(
+                    children: [
+                      const Icon(Icons.block, color: Colors.red, size: 20),
+                      const SizedBox(width: 6),
+                      Expanded(
+                        child: Text(
+                          locService.t('addNode.accountBlocked'),
+                          style: const TextStyle(color: Colors.red, fontSize: 13),
+                        ),
+                      ),
+                    ],
+                  ),
+                )
               else if (submittableProfiles.isEmpty)
                 Padding(
                   padding: const EdgeInsets.fromLTRB(16, 0, 16, 12),

lib/widgets/edit_node_sheet.dart

@@ -377,6 +377,7 @@ class _EditNodeSheetState extends State<EditNodeSheet> {
         
         final allowSubmit = kEnableNodeEdits && 
             appState.isLoggedIn && 
+            !appState.hasActiveBlock &&
             submittableProfiles.isNotEmpty && 
             session.profile != null && 
             session.profile!.isSubmittable &&
@@ -526,6 +527,22 @@ class _EditNodeSheetState extends State<EditNodeSheet> {
                     ],
                   ),
                 )
+              else if (appState.hasActiveBlock)
+                Padding(
+                  padding: const EdgeInsets.fromLTRB(16, 0, 16, 12),
+                  child: Row(
+                    children: [
+                      const Icon(Icons.block, color: Colors.red, size: 20),
+                      const SizedBox(width: 6),
+                      Expanded(
+                        child: Text(
+                          locService.t('editNode.accountBlocked'),
+                          style: const TextStyle(color: Colors.red, fontSize: 13),
+                        ),
+                      ),
+                    ],
+                  ),
+                )
               else if (submittableProfiles.isEmpty)
                 Padding(
                   padding: const EdgeInsets.fromLTRB(16, 0, 16, 12),

lib/widgets/node_tag_sheet.dart

@@ -184,6 +184,23 @@ class _NodeTagSheetState extends State<NodeTagSheet> {
             return;
           }
 
+          if (appState.hasActiveBlock) {
+            await showDialog<void>(
+              context: context,
+              builder: (BuildContext context) => AlertDialog(
+                title: Text(locService.t('node.confirmDeleteTitle')),
+                content: Text(locService.t('node.accountBlockedCannotDelete')),
+                actions: [
+                  TextButton(
+                    onPressed: () => Navigator.of(context).pop(),
+                    child: Text(locService.ok),
+                  ),
+                ],
+              ),
+            );
+            return;
+          }
+
           final result = await showDialog<({bool confirmed, String comment})>(
             context: context,
             builder: (BuildContext context) => _DeleteNodeDialog(