launcher/ui/pages/global/AccountListPage.cpp

@@ -146,6 +146,14 @@ void AccountListPage::on_actionAddMicrosoft_triggered()
 
 void AccountListPage::on_actionAddOffline_triggered()
 {
+    if (!m_accounts->anyAccountIsValid()) {
+        QMessageBox::warning(this, tr("Error"),
+                             tr("You must add a Microsoft account that owns Minecraft before you can add an offline account."
+                                "<br><br>"
+                                "If you have lost your account you can contact Microsoft for support."));
+        return;
+    }
+
     MinecraftAccountPtr account =
         OfflineLoginDialog::newAccount(this, tr("Please enter your desired username to add your offline account."));