check if channel.membercount is null

lib/src/channel_info.dart

@@ -16,7 +16,7 @@ class ChannelInfo extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    if (channel.memberCount > 2) {
+    if (channel.memberCount != null && channel.memberCount > 2) {
       return Text(
         '${channel.memberCount} Members, ${channel.state.watcherCount} Online',
         style: StreamChatTheme.of(context)

lib/src/message_list_view.dart

@@ -446,7 +446,7 @@ class _MessageListViewState extends State<MessageListView> {
                 read.lastRead.isBefore(messages[index - 1].createdAt)))
         ?.toList();
 
-    final allRead = readList.length == channel.memberCount - 1;
+    final allRead = readList.length >= (channel.memberCount ?? 0) - 1;
 
     return MessageWidget(
       message: message,