[Backport release-11.x] When auth is down, launch into offline mode (#5729)

launcher/LaunchController.cpp

@@ -40,6 +40,7 @@
 #include "minecraft/auth/AccountData.h"
 #include "minecraft/auth/AccountList.h"
 
+#include "net/NetUtils.h"
 #include "ui/InstanceWindow.h"
 #include "ui/dialogs/CustomMessageBox.h"
 #include "ui/dialogs/MSALoginDialog.h"
@@ -225,13 +226,14 @@ bool LaunchController::askPlayDemo() const
     return box.clickedButton() == demoButton;
 }
 
-QString LaunchController::askOfflineName(const QString& playerName, bool* ok) const
+QString LaunchController::askOfflineName(const QString& playerName, bool* ok)
 {
     if (ok != nullptr) {
         *ok = false;
     }
 
-    QString message;
+    QString title, message;
+    title = tr("Player name");
     switch (m_actualLaunchMode) {
         case LaunchMode::Normal:
             Q_ASSERT(false);
@@ -241,7 +243,14 @@ QString LaunchController::askOfflineName(const QString& playerName, bool* ok) co
             break;
         case LaunchMode::Offline:
             if (m_wantedLaunchMode == LaunchMode::Normal) {
-                message = tr("You are not connected to the Internet, launching in offline mode\n\n");
+                auto netErr = m_accountToUse->accountData()->networkError;
+                if (Net::isServerError(netErr)) {
+                    title = tr("Auth servers offline");
+                    message = tr("The Minecraft authentication servers are currently unavailable, launching in offline mode.\n\n");
+                } else {
+                    title = tr("No internet connection");
+                    message = tr("You are not connected to the Internet, launching in offline mode.\n\n");
+                }
             }
             message += tr("Choose your offline mode player name");
             break;
@@ -251,7 +260,7 @@ QString LaunchController::askOfflineName(const QString& playerName, bool* ok) co
     QString usedname = lastOfflinePlayerName.isEmpty() ? playerName : lastOfflinePlayerName;
 
     ChooseOfflineNameDialog dialog(message, m_parentWidget);
-    dialog.setWindowTitle(tr("Player name"));
+    dialog.setWindowTitle(title);
     dialog.setUsername(usedname);
     if (dialog.exec() != QDialog::Accepted) {
         return {};

launcher/LaunchController.h

@@ -78,7 +78,7 @@ class LaunchController : public Task {
     void decideAccount();
     LaunchDecision decideLaunchMode();
     bool askPlayDemo() const;
-    QString askOfflineName(const QString& playerName, bool* ok = nullptr) const;
+    QString askOfflineName(const QString& playerName, bool* ok = nullptr);
     bool reauthenticateAccount(const MinecraftAccountPtr& account, const QString& reason);
 
    private slots:

launcher/minecraft/auth/AccountData.h

@@ -41,6 +41,7 @@
 
 #include <QDateTime>
 #include <QMap>
+#include <QNetworkReply>
 #include <QVariantMap>
 
 enum class Validity { None, Assumed, Certain };
@@ -118,5 +119,6 @@ struct AccountData {
     // runtime only information (not saved with the account)
     QString internalId;
     QString errorString;
+    QNetworkReply::NetworkError networkError = QNetworkReply::NoError;
     AccountState accountState = AccountState::Unchecked;
 };

launcher/minecraft/auth/steps/LauncherLoginStep.cpp

@@ -56,10 +56,11 @@ void LauncherLoginStep::onRequestDone(QByteArray* response)
     qCDebug(authCredentials()) << *response;
     if (m_request->error() != QNetworkReply::NoError) {
         qWarning() << "Reply error:" << m_request->error();
-        if (Net::isApplicationError(m_request->error())) {
+        if (Net::isApplicationError(m_request->error()) && !Net::isServerError(m_request->error())) {
             emit finished(AccountTaskState::STATE_FAILED_SOFT,
                           tr("Failed to get Minecraft access token: %1").arg(m_request->errorString()));
         } else {
+            m_data->networkError = m_request->error();
             emit finished(AccountTaskState::STATE_OFFLINE, tr("Failed to get Minecraft access token: %1").arg(m_request->errorString()));
         }
         return;

launcher/minecraft/auth/steps/MinecraftProfileStep.cpp

@@ -52,10 +52,11 @@ void MinecraftProfileStep::onRequestDone(QByteArray* response)
         qWarning() << " Response:";
         qWarning() << QString::fromUtf8(*response);
 
-        if (Net::isApplicationError(m_request->error())) {
+        if (Net::isApplicationError(m_request->error()) && !Net::isServerError(m_request->error())) {
             emit finished(AccountTaskState::STATE_FAILED_SOFT,
                           tr("Minecraft Java profile acquisition failed: %1").arg(m_request->errorString()));
         } else {
+            m_data->networkError = m_request->error();
             emit finished(AccountTaskState::STATE_OFFLINE,
                           tr("Minecraft Java profile acquisition failed: %1").arg(m_request->errorString()));
         }

launcher/minecraft/auth/steps/XboxAuthorizationStep.cpp

@@ -60,13 +60,14 @@ void XboxAuthorizationStep::onRequestDone(QByteArray* response)
     qCDebug(authCredentials()) << *response;
     if (m_request->error() != QNetworkReply::NoError) {
         qWarning() << "Reply error:" << m_request->error();
-        if (Net::isApplicationError(m_request->error())) {
+        if (Net::isApplicationError(m_request->error()) && !Net::isServerError(m_request->error())) {
             if (processSTSError(*response)) {
                 return;
             }
             emit finished(AccountTaskState::STATE_FAILED_SOFT,
                           tr("Unknown STS error for %1 services: %2").arg(m_authorizationKind, m_request->errorString()));
         } else {
+            m_data->networkError = m_request->error();
             emit finished(AccountTaskState::STATE_OFFLINE,
                           tr("Failed to get authorization for %1 services: %2").arg(m_authorizationKind, m_request->errorString()));
         }

launcher/minecraft/auth/steps/XboxUserStep.cpp

@@ -56,9 +56,10 @@ void XboxUserStep::onRequestDone(QByteArray* response)
 {
     if (m_request->error() != QNetworkReply::NoError) {
         qWarning() << "Reply error:" << m_request->error();
-        if (Net::isApplicationError(m_request->error())) {
+        if (Net::isApplicationError(m_request->error()) && !Net::isServerError(m_request->error())) {
             emit finished(AccountTaskState::STATE_FAILED_SOFT, tr("Xbox user authentication failed: %1").arg(m_request->errorString()));
         } else {
+            m_data->networkError = m_request->error();
             emit finished(AccountTaskState::STATE_OFFLINE, tr("Xbox user authentication failed: %1").arg(m_request->errorString()));
         }
         return;

launcher/net/NetUtils.h

@@ -40,4 +40,18 @@ inline bool isApplicationError(QNetworkReply::NetworkError x)
                                                         QNetworkReply::UnknownContentError };
     return errors.contains(x);
 }
+
+// 500 class errors, see https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Status/500
+// microsoft may send these error codes when services (auth) are down.
+// We treat this as a reason to launch in offline mode.
+inline bool isServerError(QNetworkReply::NetworkError x)
+{
+    static QSet<QNetworkReply::NetworkError> errors = { QNetworkReply::InternalServerError,
+                                                        QNetworkReply::OperationNotImplementedError,
+                                                        QNetworkReply::ServiceUnavailableError,     // 503 | seen in logs in 2026
+                                                        //QNetworkReply::GatewayTimeoutError,       // 504 | seen in logs in 2024
+                                                        // Qt doesn't have it mapped. Unknown covers it
+                                                        QNetworkReply::UnknownServerError };
+    return errors.contains(x);
+}
 }  // namespace Net