Errors: refuse links the probe can't play (with Put it up anyway), plain error texts, and others see who can't play

report.error / state.members[].error (optional, no protocol bump): an
errored member is out of the ready gate until its player opens the media
or the media changes; others see "Bob can't play this: ..." and a mark
on the avatar; your own pill offers Retry (reload).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/desktop/lib/src/shell/app_shell.dart

@@ -379,7 +379,7 @@ class AppShellState extends State<AppShell> with SingleTickerProviderStateMixin
       if (error != null || !mounted) return error;
     }
     // Alone, a link plays direct: there is nobody to pass it on to.
-    if (media is LinkMedia && session.solo.peek()) media = LinkMedia(media.url);
+    if (media is LinkMedia && session.solo.peek()) media = LinkMedia(media.url, anyway: media.anyway);
     final error = await session.coordinator.swapPicked(media);
     if (error != null || !mounted) return error;
     final f = session.lastForm;

apps/desktop/lib/src/shell/avatar.dart

@@ -19,6 +19,9 @@ class AvatarInfo {
   final bool ready, buffering, relaying, stale, host, self;
   /// Sitting out: dimmed, with an "away" mark.
   final bool out;
+  /// Why their player cannot open the media (`members[].error`): an error
+  /// mark; empty when it can.
+  final String error;
   const AvatarInfo({
     this.id = '',
     required this.name,
@@ -31,6 +34,7 @@ class AvatarInfo {
     this.host = false,
     this.self = false,
     this.out = false,
+    this.error = '',
   });
 }
 
@@ -78,7 +82,7 @@ ImageProvider? memberAvatarImage(MemberView m, SessionCoordinator coord) {
 }
 
 /// Your own avatar from the profile (also offline).
-AvatarInfo selfAvatarInfo({bool ready = false, bool host = false, bool out = false}) {
+AvatarInfo selfAvatarInfo({bool ready = false, bool host = false, bool out = false, String error = ''}) {
   final p = Profile.instance;
   final png = p.picture.value;
   final name = p.name.value;
@@ -90,6 +94,7 @@ AvatarInfo selfAvatarInfo({bool ready = false, bool host = false, bool out = fal
     host: host,
     self: true,
     out: out,
+    error: error,
   );
 }
 
@@ -104,7 +109,7 @@ AvatarInfo memberAvatarInfo(MemberView m, StateBroadcast? r, SessionCoordinator
     color: self ? Profile.instance.color.value : colorForName(m.name),
     image: memberAvatarImage(m, coord),
     ready: m.ready,
-    buffering: !m.stale && m.ready && playing && m.buffered < r!.bufferNeed,
+    buffering: !m.stale && m.ready && m.error.isEmpty && playing && m.buffered < r!.bufferNeed,
     relaying: relay != null && relay.source.isNotEmpty && relay.source == m.id,
     stale: m.stale,
     // The state marks the host (`members[].host`); your own app also
@@ -112,6 +117,7 @@ AvatarInfo memberAvatarInfo(MemberView m, StateBroadcast? r, SessionCoordinator
     host: m.host || (self && coord.hostFile != null),
     self: self,
     out: m.out,
+    error: m.error,
   );
 }
 
@@ -138,7 +144,7 @@ class PartyWatch extends StatelessWidget {
 /// Circle avatar with a status ring outside it and a gap in the background
 /// colour, so overlapping neighbours never hide the status. Crown = host,
 /// tower = passing the video on, spinner = buffering, dimmed = stale,
-/// dimmed with a moon = sitting out.
+/// dimmed with a moon = sitting out, red "!" = cannot play the media.
 class StatusAvatar extends StatelessWidget {
   final AvatarInfo info;
   final double size;
@@ -222,6 +228,17 @@ class StatusAvatar extends StatelessWidget {
                 child: Icon(Icons.bedtime, size: (badge * 0.8).clamp(10.0, 24.0), color: Colors.blueGrey.shade200),
               ),
             ),
+          if (info.error.isNotEmpty)
+            Positioned(
+              key: const ValueKey('error-mark'),
+              right: -3,
+              top: -3,
+              child: Container(
+                padding: const EdgeInsets.all(1),
+                decoration: BoxDecoration(shape: BoxShape.circle, color: bg),
+                child: Icon(Icons.error, size: (badge * 0.8).clamp(10.0, 24.0), color: Colors.redAccent.shade200),
+              ),
+            ),
           if (badges && info.relaying)
             Positioned(
               right: -3,
@@ -287,7 +304,9 @@ class _AvatarStackState extends State<AvatarStack> {
                   left: i * step,
                   top: 0,
                   child: Tooltip(
-                    message: visible[i].name,
+                    message: visible[i].error.isEmpty
+                        ? visible[i].name
+                        : "${visible[i].name} can't play this: ${visible[i].error}",
                     child: StatusAvatar(info: visible[i], size: size),
                   ),
                 ),

apps/desktop/lib/src/shell/library_link.dart

@@ -3,7 +3,7 @@ import 'dart:convert';
 
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
-import 'package:sync_relay_core/core.dart' show LinkProbe, hasMediaExtension, notAVideoText;
+import 'package:sync_relay_core/core.dart' show LinkProbe, hasMediaExtension, parseJellyfinLink, playErrorText;
 
 import '../playback/yt_dlp_app.dart';
 import '../screens/home/media_picker.dart';
@@ -107,7 +107,10 @@ class LinkPreview {
   /// "youtube.com · Channel", or the host.
   final String subtitle;
   final String? thumbnail;
-  const LinkPreview({required this.title, required this.subtitle, this.thumbnail});
+  /// Why this computer cannot open it, in plain words ([LinkProbe.problem]);
+  /// null when it looks playable.
+  final String? problem;
+  const LinkPreview({required this.title, required this.subtitle, this.thumbnail, this.problem});
 }
 
 /// What a link is (see [AppYtDlp.probe]).
@@ -125,24 +128,30 @@ String clockText(double seconds) {
 }
 
 /// The preview of [url]: a web page shows yt-dlp's title, uploader,
-/// duration and thumbnail (or why it is not a video); a media file (by
-/// name or by probe) its file name and host. Null for text that is not an http(s) link.
+/// duration and thumbnail; a media file its file name and host; a link
+/// that does not open, why ([LinkPreview.problem]). Null for text that is
+/// not an http(s) link.
 Future<LinkPreview?> previewLink(String url, {LinkProber probe = defaultLinkProber}) async {
   final uri = Uri.tryParse(url.trim());
   if (uri == null || !(uri.scheme == 'http' || uri.scheme == 'https') || uri.host.isEmpty) return null;
   final host = _host(uri);
-  // A media file name needs no lookup.
-  if (hasMediaExtension(uri)) return LinkPreview(title: LinkMedia(url.trim()).label, subtitle: host);
+  // A Jellyfin item goes up as the item (see `mediaForLink`), not the page.
+  if (parseJellyfinLink(url.trim()) != null) return LinkPreview(title: host, subtitle: '$host · Jellyfin');
+  final file = hasMediaExtension(uri);
   final LinkProbe p;
   try {
     p = await probe(url.trim());
   } catch (e) {
-    return LinkPreview(title: LinkMedia(url.trim()).label, subtitle: '$host · $e');
+    final problem = playErrorText('$e');
+    return LinkPreview(title: LinkMedia(url.trim()).label, subtitle: '$host · $problem', problem: problem);
   }
   final info = p.info;
   if (!p.isPage) return LinkPreview(title: LinkMedia(url.trim()).label, subtitle: host);
-  if (info == null) {
-    return LinkPreview(title: p.title ?? host, subtitle: '$host · ${notAVideoText(p.ytDlpError)}');
+  final problem = p.problem;
+  if (info == null || problem != null) {
+    // A media file name that did not answer as one keeps its name.
+    final title = file ? LinkMedia(url.trim()).label : p.title ?? host;
+    return LinkPreview(title: title, subtitle: '$host · ${problem ?? 'Not a video'}', problem: problem);
   }
   return LinkPreview(
     title: p.title ?? host,
@@ -221,6 +230,8 @@ class _LibraryLinkSourceState extends State<LibraryLinkSource> {
   Timer? _debounce;
   bool _busy = false;
   String? _error;
+  /// [_error] is the probe's problem: "Put it up anyway" is offered.
+  bool _canForce = false;
 
   @override
   void initState() {
@@ -242,7 +253,12 @@ class _LibraryLinkSourceState extends State<LibraryLinkSource> {
     if (url == _previewUrl) return;
     _debounce?.cancel();
     _debounce = Timer(const Duration(milliseconds: 350), () => _preview(url));
-    if (mounted) setState(() => _error = null);
+    if (mounted) {
+      setState(() {
+        _error = null;
+        _canForce = false;
+      });
+    }
   }
 
   Future<void> _preview(String url) async {
@@ -263,19 +279,27 @@ class _LibraryLinkSourceState extends State<LibraryLinkSource> {
     } catch (_) {}
   }
 
-  Future<void> _go() async {
+  Future<void> _go({bool anyway = false}) async {
     final url = _c.link.text.trim();
     if (url.isEmpty || _busy) return;
     setState(() {
       _busy = true;
       _error = null;
+      _canForce = false;
     });
-    String? error;
-    try {
-      error = await widget.onPutUp(LinkMedia(url, relay: widget.solo ? LinkRelay.direct : _c.linkRelay));
-    } catch (e) {
-      error = '$e';
+    // What the probe found refuses it here, with "Put it up anyway": the
+    // server or a friend (with cookies) may still open it.
+    final problem = anyway ? null : (_previews[url] ?? await previewLink(url, probe: widget.probe))?.problem;
+    String? error = problem;
+    if (problem == null) {
+      try {
+        error = await widget.onPutUp(
+            LinkMedia(url, relay: widget.solo ? LinkRelay.direct : _c.linkRelay, anyway: anyway));
+      } catch (e) {
+        error = '$e';
+      }
     }
+    final canForce = problem != null;
     if (error == null) {
       final p = _previews[url] ?? await previewLink(url, probe: widget.probe);
       unawaited(widget.recents.add(RecentLink(
@@ -289,6 +313,7 @@ class _LibraryLinkSourceState extends State<LibraryLinkSource> {
     setState(() {
       _busy = false;
       _error = error;
+      _canForce = canForce;
     });
   }
 
@@ -373,6 +398,14 @@ class _LibraryLinkSourceState extends State<LibraryLinkSource> {
                   textAlign: TextAlign.center,
                   style: t.bodySmall?.copyWith(color: _error != null ? scheme.error : Colors.grey),
                 ),
+                if (_canForce)
+                  Center(
+                    child: TextButton(
+                      key: const ValueKey('link-put-up-anyway'),
+                      onPressed: _busy ? null : () => _go(anyway: true),
+                      child: Text(solo ? 'Play it anyway' : 'Put it up anyway'),
+                    ),
+                  ),
               ],
               AnimatedSize(
                 duration: easeTime,
@@ -475,9 +508,9 @@ class _PreviewCard extends StatelessWidget {
                       const SizedBox(height: 4),
                       Text(
                         p?.subtitle ?? 'Paste an http(s) address',
-                        maxLines: 1,
+                        maxLines: 2,
                         overflow: TextOverflow.ellipsis,
-                        style: const TextStyle(color: Colors.grey),
+                        style: TextStyle(color: p?.problem != null ? scheme.error : Colors.grey),
                       ),
                     ],
                   ),

apps/desktop/lib/src/shell/party_strip.dart

@@ -103,6 +103,7 @@ class PartyStrip extends StatelessWidget {
                   info: selfAvatarInfo(
                     ready: self?.ready ?? false,
                     host: online && !solo && coord.hostFile != null,
+                    error: online ? coord.playerError.value : '',
                   ),
                   size: stripAvatarSize,
                   ring: online,
@@ -553,6 +554,8 @@ class _MemberTile extends StatelessWidget {
         ? 'reconnecting…'
         : m.out
         ? 'sitting out'
+        : m.error.isNotEmpty
+        ? "can't play this: ${m.error}"
         : info.buffering
         ? 'buffering ${m.buffered.toStringAsFixed(1)} s'
         : m.ready

apps/desktop/lib/src/shell/player_status.dart

@@ -11,11 +11,12 @@ import 'avatar.dart';
 import 'motion.dart';
 
 /// What the player's status pill says, most pressing first.
-enum StatusKind { reconnecting, problem, connecting, finished, loading, you, waiting }
+enum StatusKind { reconnecting, problem, connecting, finished, loading, you, cannotPlay, waiting }
 
-/// The pill's button: stop reconnecting, retry, or mark yourself ready
-/// (the whole pill).
-enum StatusAction { cancel, retry, ready }
+/// The pill's button: stop reconnecting, retry (reconnect), reload the
+/// video (your player could not open it), or mark yourself ready (the
+/// whole pill).
+enum StatusAction { cancel, retry, reload, ready }
 
 /// One status line: [text], a muted [detail], a coloured [tone] for
 /// problems (warn, error), the members it is about ([who]; [self] for you)
@@ -55,18 +56,24 @@ String _sentence(String s) => s.isEmpty ? s : s[0].toUpperCase() + s.substring(1
 
 /// The player's status from the session's signals; null when there is
 /// nothing to say (playing, connected, everyone ready). [slowConnect]:
-/// connecting has taken over 2 s.
+/// connecting has taken over 2 s. [playerError]: why your player cannot
+/// open the media (the coordinator's `playerError`).
 StatusView? playerStatusFor({
   required HealthStatus health,
   bool reconnecting = false,
   StateBroadcast? state,
   MemberView? self,
   bool slowConnect = false,
+  String playerError = '',
 }) {
   if (reconnecting) {
     return const StatusView(StatusKind.reconnecting, 'Reconnecting…',
         tone: HealthSeverity.warn, action: StatusAction.cancel);
   }
+  if (playerError.isNotEmpty && state?.media != null && !(self?.out ?? false)) {
+    return StatusView(StatusKind.problem, "Can't play this: $playerError",
+        tone: HealthSeverity.error, action: StatusAction.reload, short: "Can't play this");
+  }
   if (health.severity == HealthSeverity.warn || health.severity == HealthSeverity.error) {
     return StatusView(StatusKind.problem, _sentence(health.message),
         tone: health.severity, action: StatusAction.retry);
@@ -81,6 +88,12 @@ StatusView? playerStatusFor({
   if (r.transport == 'finished') {
     return const StatusView(StatusKind.finished, 'Finished · seek back or pick the next video', short: 'Finished');
   }
+  // Members whose player cannot open it: the server does not wait for
+  // them; say why instead of "waiting for".
+  final failed = [
+    for (final m in r.members)
+      if (m.error.isNotEmpty && !m.out && (self == null || m.id != self.id)) m,
+  ];
   // As the server holds playback: someone in the ready set short of the
   // minimum buffer.
   final need = r.bufferNeed;
@@ -92,12 +105,22 @@ StatusView? playerStatusFor({
           who: [m], self: you, progress: p, detail: '${(p * 100).round()}%');
     }
   }
+  if (failed.isNotEmpty) {
+    final f = failed.first;
+    final who = nameList([for (final m in failed) m.name]);
+    final unready = self != null && !self.ready;
+    return StatusView(StatusKind.cannotPlay, "$who can't play this: ${f.error}",
+        who: failed,
+        short: "$who can't play this",
+        detail: unready ? "Press Space when you're ready" : null,
+        action: unready ? StatusAction.ready : null);
+  }
   if (self != null && !self.ready) {
     return StatusView(StatusKind.you, "Press Space when you're ready",
         who: [self], self: true, action: StatusAction.ready, detail: 'or click here', short: 'Press Space when ready');
   }
   // Members sitting out are never waited for nor counted.
-  final active = [for (final m in r.members) if (!m.stale && !m.out) m];
+  final active = [for (final m in r.members) if (!m.stale && !m.out && m.error.isEmpty) m];
   final others = [
     for (final m in active)
       if ((self == null || m.id != self.id) && !(m.inSet && m.ready)) m,
@@ -117,6 +140,7 @@ StatusView? playerStatusNow({bool slowConnect = false}) {
     state: c.serverState.value,
     self: c.selfMember.value,
     slowConnect: slowConnect,
+    playerError: c.playerError.value,
   );
 }
 
@@ -164,6 +188,8 @@ class _PlayerStatusState extends State<PlayerStatus> {
         coord.cancelReconnect();
       case StatusAction.retry:
         coord.retry();
+      case StatusAction.reload:
+        unawaited(coord.reloadVideo());
       case StatusAction.ready:
         coord.toggleReady();
     }
@@ -266,6 +292,7 @@ class _StatusLine extends StatelessWidget {
         return null;
       case StatusKind.loading:
       case StatusKind.you:
+      case StatusKind.cannotPlay:
       case StatusKind.waiting:
         final r = coord.serverState.value;
         final infos = [