Index: common/BuildSettings.h
===================================================================
--- common/BuildSettings.h	(revision 15722)
+++ common/BuildSettings.h	(working copy)
@@ -209,8 +209,6 @@
 
 #if defined(MODPLUG_TRACKER)
 
-#define MPT_UPDATE_LEGACY 1
-
 // Enable built-in test suite.
 #if defined(MPT_BUILD_DEBUG) || defined(MPT_BUILD_CHECKED)
 #define ENABLE_TESTS
Index: mptrack/TrackerSettings.cpp
===================================================================
--- mptrack/TrackerSettings.cpp	(revision 15722)
+++ mptrack/TrackerSettings.cpp	(working copy)
@@ -326,14 +326,7 @@
 	, UpdateUpdateCheckPeriod_DEPRECATED(conf, U_("Update"), U_("UpdateCheckPeriod"), 7)
 	, UpdateIntervalDays(conf, U_("Update"), U_("UpdateCheckIntervalDays"), 7)
 	, UpdateChannel(conf, U_("Update"), U_("Channel"), UpdateChannelRelease)
-#if MPT_UPDATE_LEGACY
-	, UpdateUpdateURL_DEPRECATED(conf, U_("Update"), U_("UpdateURL"), CUpdateCheck::GetDefaultChannelReleaseURL())
-	, UpdateChannelReleaseURL(conf, U_("Update"), U_("ChannelReleaseURL"), CUpdateCheck::GetDefaultChannelReleaseURL())
-	, UpdateChannelNextURL(conf, U_("Update"), U_("ChannelStableURL"), CUpdateCheck::GetDefaultChannelNextURL())
-	, UpdateChannelDevelopmentURL(conf, U_("Update"), U_("ChannelDevelopmentURL"), CUpdateCheck::GetDefaultChannelDevelopmentURL())
-#else // !MPT_UPDATE_LEGACY
 	, UpdateUpdateURL_DEPRECATED(conf, U_("Update"), U_("UpdateURL"), U_("https://update.openmpt.org/check/$VERSION/$GUID"))
-#endif // MPT_UPDATE_LEGACY
 	, UpdateAPIURL(conf, U_("Update"), U_("APIURL"), CUpdateCheck::GetDefaultAPIURL())
 	, UpdateStatisticsConsentAsked(conf, U_("Update"), U_("StatistisConsentAsked"), false)
 	, UpdateStatistics(conf, U_("Update"), U_("Statistis"), false)
@@ -340,9 +333,6 @@
 	, UpdateSendGUID_DEPRECATED(conf, U_("Update"), U_("SendGUID"), false)
 	, UpdateShowUpdateHint(conf, U_("Update"), U_("ShowUpdateHint"), true)
 	, UpdateIgnoreVersion(conf, U_("Update"), U_("IgnoreVersion"), _T(""))
-#if MPT_UPDATE_LEGACY
-	, UpdateLegacyMethod(conf, U_("Update"), U_("LegacyMethod"), false)
-#endif // MPT_UPDATE_LEGACY
 	, UpdateSkipSignatureVerificationUNSECURE(conf, U_("Update"), U_("SkipSignatureVerification"), false)
 	, UpdateSigningKeysRootAnchors(conf, U_("Update"), U_("SigningKeysRootAnchors"), CUpdateCheck::GetDefaultUpdateSigningKeysRootAnchors())
 #endif // MPT_ENABLE_UPDATE
@@ -822,9 +812,6 @@
 		} else
 		{
 			UpdateChannel = UpdateChannelDevelopment;
-#if MPT_UPDATE_LEGACY
-			UpdateChannelDevelopmentURL = url;
-#endif // MPT_UPDATE_LEGACY
 		}
 		UpdateStatistics = UpdateSendGUID_DEPRECATED.Get();
 		conf.Forget(UpdateUpdateCheckPeriod_DEPRECATED.GetPath());
Index: mptrack/TrackerSettings.h
===================================================================
--- mptrack/TrackerSettings.h	(revision 15722)
+++ mptrack/TrackerSettings.h	(working copy)
@@ -901,11 +901,6 @@
 	Setting<int32> UpdateIntervalDays;
 	Setting<uint32> UpdateChannel;
 	Setting<mpt::ustring> UpdateUpdateURL_DEPRECATED;
-#if MPT_UPDATE_LEGACY
-	Setting<mpt::ustring> UpdateChannelReleaseURL;
-	Setting<mpt::ustring> UpdateChannelNextURL;
-	Setting<mpt::ustring> UpdateChannelDevelopmentURL;
-#endif // MPT_UPDATE_LEGACY
 	Setting<mpt::ustring> UpdateAPIURL;
 	Setting<bool> UpdateStatisticsConsentAsked;
 	Setting<bool> UpdateStatistics;
@@ -912,9 +907,6 @@
 	Setting<bool> UpdateSendGUID_DEPRECATED;
 	Setting<bool> UpdateShowUpdateHint;
 	Setting<CString> UpdateIgnoreVersion;
-#if MPT_UPDATE_LEGACY
-	Setting<bool> UpdateLegacyMethod;
-#endif // MPT_UPDATE_LEGACY
 	Setting<bool> UpdateSkipSignatureVerificationUNSECURE;
 	Setting<std::vector<mpt::ustring>> UpdateSigningKeysRootAnchors;
 
Index: mptrack/UpdateCheck.cpp
===================================================================
--- mptrack/UpdateCheck.cpp	(revision 15722)
+++ mptrack/UpdateCheck.cpp	(working copy)
@@ -399,26 +399,6 @@
 }
 
 
-#if MPT_UPDATE_LEGACY
-
-mpt::ustring CUpdateCheck::GetDefaultChannelReleaseURL()
-{
-	return U_("https://update.openmpt.org/check/$VERSION/$GUID");
-}
-
-mpt::ustring CUpdateCheck::GetDefaultChannelNextURL()
-{
-	return U_("https://update.openmpt.org/check/next/$VERSION/$GUID");
-}
-
-mpt::ustring CUpdateCheck::GetDefaultChannelDevelopmentURL()
-{
-	return U_("https://update.openmpt.org/check/testing/$VERSION/$GUID");
-}
-
-#endif // MPT_UPDATE_LEGACY
-
-
 std::vector<mpt::ustring> CUpdateCheck::GetDefaultUpdateSigningKeysRootAnchors()
 {
 	// IMPORTANT:
@@ -480,15 +460,7 @@
 		const double secsSinceLastCheck = difftime(now, lastCheck);
 		if(secsSinceLastCheck > 0.0 && secsSinceLastCheck < updateCheckPeriod * 86400.0)
 		{
-#if MPT_UPDATE_LEGACY
-			if(TrackerSettings::Instance().UpdateLegacyMethod)
-			{
-				return;
-			} else
-#endif // MPT_UPDATE_LEGACY
-			{
-				loadPersisted = true;
-			}
+			loadPersisted = true;
 		}
 
 		// Never ran update checks before, so we notify the user of automatic update checks.
@@ -561,12 +533,6 @@
 	: periodDays(TrackerSettings::Instance().UpdateIntervalDays)
 	, channel(static_cast<UpdateChannel>(TrackerSettings::Instance().UpdateChannel.Get()))
 	, persistencePath(theApp.GetConfigPath())
-#if MPT_UPDATE_LEGACY
-	, modeLegacy(TrackerSettings::Instance().UpdateLegacyMethod)
-	, channelReleaseURL(TrackerSettings::Instance().UpdateChannelReleaseURL)
-	, channelNextURL(TrackerSettings::Instance().UpdateChannelNextURL)
-	, channelDevelopmentURL(TrackerSettings::Instance().UpdateChannelDevelopmentURL)
-#endif // MPT_UPDATE_LEGACY
 	, apiURL(TrackerSettings::Instance().UpdateAPIURL)
 	, sendStatistics(TrackerSettings::Instance().UpdateStatistics)
 	, statisticsUUID(TrackerSettings::Instance().VersionInstallGUID)
@@ -661,62 +627,10 @@
 }
 
 
-#if MPT_UPDATE_LEGACY
-mpt::ustring CUpdateCheck::GetUpdateURLV2(const CUpdateCheck::Settings &settings)
-{
-	mpt::ustring updateURL;
-	if(settings.channel == UpdateChannelRelease)
-	{
-		updateURL = settings.channelReleaseURL;
-		if(updateURL.empty())
-		{
-			updateURL = GetDefaultChannelReleaseURL();
-		}
-	}	else if(settings.channel == UpdateChannelNext)
-	{
-		updateURL = settings.channelNextURL;
-		if(updateURL.empty())
-		{
-			updateURL = GetDefaultChannelNextURL();
-		}
-	}	else if(settings.channel == UpdateChannelDevelopment)
-	{
-		updateURL = settings.channelDevelopmentURL;
-		if(updateURL.empty())
-		{
-			updateURL = GetDefaultChannelDevelopmentURL();
-		}
-	}	else
-	{
-		updateURL = settings.channelReleaseURL;
-		if(updateURL.empty())
-		{
-			updateURL = GetDefaultChannelReleaseURL();
-		}
-	}
-	if(updateURL.find(U_("://")) == mpt::ustring::npos)
-	{
-		updateURL = U_("https://") + updateURL;
-	}
-	// Build update URL
-	updateURL = mpt::String::Replace(updateURL, U_("$VERSION"), MPT_UFORMAT("{}-{}-{}")
-		( Version::Current()
-		, BuildVariants().GuessCurrentBuildName()
-		, settings.sendStatistics ? mpt::OS::Windows::Version::Current().GetNameShort() : U_("unknown")
-		));
-	updateURL = mpt::String::Replace(updateURL, U_("$GUID"), settings.sendStatistics ? mpt::ufmt::val(settings.statisticsUUID) : U_("anonymous"));
-	return updateURL;
-}
-#endif // MPT_UPDATE_LEGACY
-
-
 // Run update check (independent thread)
 UpdateCheckResult CUpdateCheck::SearchUpdate(const CUpdateCheck::Context &context, const CUpdateCheck::Settings &settings, const std::string &statistics)
 {
 	UpdateCheckResult result;
-
-#if MPT_UPDATE_LEGACY
-	if(settings.modeLegacy)
 	{
 		if(!context.window->SendMessage(context.msgProgress, context.autoUpdate ? 1 : 0, 0))
 		{
@@ -726,43 +640,6 @@
 		{
 			throw CUpdateCheck::Cancel();
 		}
-		{
-			HTTP::InternetSession internet(Version::Current().GetOpenMPTVersionString());
-			if(!context.window->SendMessage(context.msgProgress, context.autoUpdate ? 1 : 0, 30))
-			{
-				throw CUpdateCheck::Cancel();
-			}
-			result = SearchUpdateLegacy(internet, settings);
-			if(!context.window->SendMessage(context.msgProgress, context.autoUpdate ? 1 : 0, 50))
-			{
-				throw CUpdateCheck::Cancel();
-			}
-			SendStatistics(internet, settings, statistics);
-			if(!context.window->SendMessage(context.msgProgress, context.autoUpdate ? 1 : 0, 70))
-			{
-				throw CUpdateCheck::Cancel();
-			}
-		}
-		if(!context.window->SendMessage(context.msgProgress, context.autoUpdate ? 1 : 0, 90))
-		{
-			throw CUpdateCheck::Cancel();
-		}
-		CleanOldUpdates(settings, context);
-		if(!context.window->SendMessage(context.msgProgress, context.autoUpdate ? 1 : 0, 100))
-		{
-			throw CUpdateCheck::Cancel();
-		}
-	} else
-#endif // MPT_UPDATE_LEGACY
-	{
-		if(!context.window->SendMessage(context.msgProgress, context.autoUpdate ? 1 : 0, 0))
-		{
-			throw CUpdateCheck::Cancel();
-		}
-		if(!context.window->SendMessage(context.msgProgress, context.autoUpdate ? 1 : 0, 10))
-		{
-			throw CUpdateCheck::Cancel();
-		}
 		bool loaded = false;
 		// try to load cached results before establishing any connection
 		if(context.loadPersisted)
@@ -860,17 +737,6 @@
 {
 	if(settings.sendStatistics)
 	{
-		if(!settings.modeLegacy)
-		{
-			HTTP::Request requestLegacyUpdate;
-			requestLegacyUpdate.SetURI(ParseURI(GetUpdateURLV2(settings)));
-			requestLegacyUpdate.method = HTTP::Method::Get;
-			requestLegacyUpdate.flags = HTTP::NoCache;
-#if defined(MPT_BUILD_RETRO)
-			requestLegacyUpdate.InsecureTLSDowngradeWindowsXP();
-#endif // MPT_BUILD_RETRO
-			HTTP::Result resultLegacyUpdateHTTP = internet(requestLegacyUpdate);
-		}
 		HTTP::Request requestStatistics;
 		if(settings.statisticsUUID.IsValid())
 		{
@@ -894,70 +760,6 @@
 }
 
 
-#if MPT_UPDATE_LEGACY
-UpdateCheckResult CUpdateCheck::SearchUpdateLegacy(HTTP::InternetSession &internet, const CUpdateCheck::Settings &settings)
-{
-
-	HTTP::Request request;
-	request.SetURI(ParseURI(GetUpdateURLV2(settings)));
-	request.method = HTTP::Method::Get;
-	request.flags = HTTP::NoCache;
-
-#if defined(MPT_BUILD_RETRO)
-	request.InsecureTLSDowngradeWindowsXP();
-#endif // MPT_BUILD_RETRO
-	HTTP::Result resultHTTP = internet(request);
-
-	// Retrieve HTTP status code.
-	if(resultHTTP.Status >= 400)
-	{
-		throw CUpdateCheck::Error(MPT_CFORMAT("Version information could not be found on the server (HTTP status code {}). Maybe your version of OpenMPT is too old!")(resultHTTP.Status));
-	}
-
-	// Now, evaluate the downloaded data.
-	UpdateCheckResult result;
-	result.UpdateAvailable = false;
-	result.CheckTime = time(nullptr);
-	CString resultData = mpt::ToCString(mpt::Charset::UTF8, mpt::buffer_cast<std::string>(resultHTTP.Data));
-	if(resultData.CompareNoCase(_T("noupdate")) != 0)
-	{
-		CString token;
-		int parseStep = 0, parsePos = 0;
-		while(!(token = resultData.Tokenize(_T("\n"), parsePos)).IsEmpty())
-		{
-			token.Trim();
-			switch(parseStep++)
-			{
-			case 0:
-				if(token.CompareNoCase(_T("update")) != 0)
-				{
-					throw CUpdateCheck::Error(_T("Could not understand server response. Maybe your version of OpenMPT is too old!"));
-				}
-				break;
-			case 1:
-				result.Version = token;
-				break;
-			case 2:
-				result.Date = token;
-				break;
-			case 3:
-				result.URL = token;
-				break;
-			}
-		}
-		if(parseStep < 4)
-		{
-			throw CUpdateCheck::Error(_T("Could not understand server response. Maybe your version of OpenMPT is too old!"));
-		}
-		result.UpdateAvailable = true;
-	}
-
-	return result;
-
-}
-#endif // MPT_UPDATE_LEGACY
-
-
 UpdateCheckResult CUpdateCheck::SearchUpdateModern(HTTP::InternetSession &internet, const CUpdateCheck::Settings &settings)
 {
 
@@ -1523,41 +1325,6 @@
 {
 	bool modal = !autoUpdate;
 
-#if MPT_UPDATE_LEGACY
-
-	if(TrackerSettings::Instance().UpdateLegacyMethod)
-	{
-		if(!result.UpdateAvailable)
-		{
-			if(modal)
-			{
-				Reporting::Information(U_("You already have the latest version of OpenMPT installed."), U_("OpenMPT Update"));
-			}
-			return;
-		}
-
-		// always show indicator, do not highlight it with a tooltip if we show a modal window later
-		if(!CMainFrame::GetMainFrame()->ShowUpdateIndicator(result, result.Version, result.URL, !modal))
-		{
-			// on failure to show indicator, continue and show modal dialog
-			modal = true;
-		}
-
-		if(!modal)
-		{
-			return;
-		}
-		UpdateDialog dlg(result.Version, result.Date, result.URL);
-		if(dlg.DoModal() != IDOK)
-		{
-			return;
-		}
-		CTrackApp::OpenURL(result.URL);
-		return;
-	}
-
-#endif // MPT_UPDATE_LEGACY
-
 	Update::versions updateData = nlohmann::json::parse(mpt::buffer_cast<std::string>(result.json)).get<Update::versions>();
 	UpdateInfo updateInfo = GetBestDownload(updateData);
 
@@ -1808,14 +1575,7 @@
 	statistics += U_("Update:") + UL_("\n");
 	statistics += UL_("\n");
 
-#if MPT_UPDATE_LEGACY
-	if(settings.modeLegacy)
 	{
-		statistics += U_("GET ") + CUpdateCheck::GetUpdateURLV2(settings) + UL_("\n");
-		statistics += UL_("\n");
-	} else
-#endif // MPT_UPDATE_LEGACY
-	{
 		statistics += U_("GET ") + settings.apiURL + MPT_UFORMAT("update/{}")(GetChannelName(static_cast<UpdateChannel>(settings.channel))) + UL_("\n");
 		statistics += UL_("\n");
 		std::vector<mpt::ustring> keyAnchors = TrackerSettings::Instance().UpdateSigningKeysRootAnchors;
@@ -1830,13 +1590,6 @@
 	{
 		statistics += U_("Statistics:") + UL_("\n");
 		statistics += UL_("\n");
-#if MPT_UPDATE_LEGACY
-		if(!settings.modeLegacy)
-#endif // MPT_UPDATE_LEGACY
-		{
-			statistics += U_("GET ") + CUpdateCheck::GetUpdateURLV2(settings) + UL_("\n");
-			statistics += UL_("\n");
-		}
 		if(settings.statisticsUUID.IsValid())
 		{
 			statistics += U_("PUT ") + settings.apiURL + MPT_UFORMAT("statistics/{}")(settings.statisticsUUID) + UL_("\n");
Index: mptrack/UpdateCheck.h
===================================================================
--- mptrack/UpdateCheck.h	(revision 15722)
+++ mptrack/UpdateCheck.h	(working copy)
@@ -42,14 +42,10 @@
 {
 	time_t CheckTime = time_t{};
 	std::vector<std::byte> json;
-#if MPT_UPDATE_LEGACY
-	bool UpdateAvailable = false;
-	CString Version;
-	CString Date;
-	CString URL;
-#endif  // MPT_UPDATE_LEGACY
-
-	bool IsFromCache() const noexcept { return CheckTime == time_t{}; }
+	bool IsFromCache() const noexcept
+	{
+		return CheckTime == time_t{};
+	}
 };
 
 class CUpdateCheck
@@ -63,12 +59,6 @@
 
 	static mpt::ustring GetStatisticsUserInformation(bool shortText);
 
-#if MPT_UPDATE_LEGACY
-	static mpt::ustring GetDefaultChannelReleaseURL();
-	static mpt::ustring GetDefaultChannelNextURL();
-	static mpt::ustring GetDefaultChannelDevelopmentURL();
-#endif // MPT_UPDATE_LEGACY
-
 	static std::vector<mpt::ustring> GetDefaultUpdateSigningKeysRootAnchors();
 	static mpt::ustring GetDefaultAPIURL();
 	
@@ -99,12 +89,6 @@
 		int32 periodDays;
 		UpdateChannel channel;
 		mpt::PathString persistencePath;
-#if MPT_UPDATE_LEGACY
-		bool modeLegacy;
-		mpt::ustring channelReleaseURL;
-		mpt::ustring channelNextURL;
-		mpt::ustring channelDevelopmentURL;
-#endif // MPT_UPDATE_LEGACY
 		mpt::ustring apiURL;
 		bool sendStatistics;
 		mpt::UUID statisticsUUID;
@@ -143,11 +127,6 @@
 
 public:
 
-#if MPT_UPDATE_LEGACY
-	// v2
-	static mpt::ustring GetUpdateURLV2(const Settings &settings);
-#endif // MPT_UPDATE_LEGACY
-
 	// v3
 	static std::string GetStatisticsDataV3(const Settings &settings);  // UTF8
 
@@ -171,9 +150,6 @@
 
 	static void SendStatistics(HTTP::InternetSession &internet, const CUpdateCheck::Settings &settings, const std::string &statistics); // may throw
 
-#if MPT_UPDATE_LEGACY
-	static UpdateCheckResult SearchUpdateLegacy(HTTP::InternetSession &internet, const CUpdateCheck::Settings &settings); // may throw
-#endif // MPT_UPDATE_LEGACY
 	static UpdateCheckResult SearchUpdateModern(HTTP::InternetSession &internet, const CUpdateCheck::Settings &settings); // may throw
 
 };