diff --git a/rainloop/v/0.0.0/app/libraries/RainLoop/Actions.php b/rainloop/v/0.0.0/app/libraries/RainLoop/Actions.php
index f175c0b83..aced6b6bf 100644
--- a/rainloop/v/0.0.0/app/libraries/RainLoop/Actions.php
+++ b/rainloop/v/0.0.0/app/libraries/RainLoop/Actions.php
@@ -8923,6 +8923,14 @@ class Actions
 				$sDefault = $sDefault.'_'.$sDefault;
 			}
 
+			$sLanguage = \preg_replace_callback('/_([a-zA-Z0-9]{2})$/', function ($aData) {
+				return \strtoupper($aData[0]);
+			}, $sLanguage);
+
+			$sDefault = \preg_replace_callback('/_([a-zA-Z0-9]{2})$/', function ($aData) {
+				return \strtoupper($aData[0]);
+			}, $sDefault);
+
 			if (\in_array($sLanguage, $aLang))
 			{
 				$sResult = $sLanguage;
@@ -8935,8 +8943,8 @@ class Actions
 
 			if (empty($sResult) && !$bAllowEmptyResult)
 			{
-				$sResult = $this->Config()->Get('webmail', $bAdmin ? 'language_admin' : 'language', 'en_us');
-				$sResult = \in_array($sResult, $aLang) ? $sResult : 'en_us';
+				$sResult = $this->Config()->Get('webmail', $bAdmin ? 'language_admin' : 'language', 'en_US');
+				$sResult = \in_array($sResult, $aLang) ? $sResult : 'en_US';
 			}
 		}
 
@@ -9063,7 +9071,7 @@ class Actions
 				{
 					if ('.' !== $sFile{0} && \is_file($sDir.'/'.$sFile) && '.yml' === \substr($sFile, -4))
 					{
-						$sLang = \strtolower(\substr($sFile, 0, -4));
+						$sLang = \substr($sFile, 0, -4);
 						if (0 < \strlen($sLang) && 'always' !== $sLang && '_source.en' !== $sLang)
 						{
 							\array_push($aList, $sLang);
@@ -9482,11 +9490,13 @@ class Actions
 
 		if (null === $aLang)
 		{
+			$sLang = $this->ValidateLanguage($sLang, 'en');
+
 			$aLang = array();
 //			\RainLoop\Utils::ReadAndAddLang(APP_VERSION_ROOT_PATH.'app/i18n/langs.ini', $aLang);
 //			\RainLoop\Utils::ReadAndAddLang(APP_VERSION_ROOT_PATH.'langs/'.$sLang.'.ini', $aLang);
 			\RainLoop\Utils::ReadAndAddLang(APP_VERSION_ROOT_PATH.'app/localization/langs.yml', $aLang);
-			\RainLoop\Utils::ReadAndAddLang(APP_VERSION_ROOT_PATH.'app/localization/webmail/'.$sLang.'.ini', $aLang);
+			\RainLoop\Utils::ReadAndAddLang(APP_VERSION_ROOT_PATH.'app/localization/webmail/'.$sLang.'.yml', $aLang);
 
 			$this->Plugins()->ReadLang($sLang, $aLang);
 		}
diff --git a/rainloop/v/0.0.0/app/libraries/RainLoop/ServiceActions.php b/rainloop/v/0.0.0/app/libraries/RainLoop/ServiceActions.php
index 68a527e7e..ebcc0941e 100644
--- a/rainloop/v/0.0.0/app/libraries/RainLoop/ServiceActions.php
+++ b/rainloop/v/0.0.0/app/libraries/RainLoop/ServiceActions.php
@@ -226,6 +226,8 @@ class ServiceActions
 	 */
 	public function ServiceOwnCloudAuth()
 	{
+		$this->oHttp->ServerNoCache();
+
 		if (!\RainLoop\Utils::IsOwnCloud() ||
 			!isset($_ENV['___rainloop_owncloud_email']) ||
 			!isset($_ENV['___rainloop_owncloud_password']) ||
@@ -840,6 +842,8 @@ class ServiceActions
 	 */
 	public function ServiceMailto()
 	{
+		$this->oHttp->ServerNoCache();
+
 		$sTo = \trim($this->oHttp->GetQuery('to', ''));
 		if (!empty($sTo) && \preg_match('/^mailto:/i', $sTo))
 		{
@@ -859,6 +863,8 @@ class ServiceActions
 	 */
 	public function ServicePing()
 	{
+		$this->oHttp->ServerNoCache();
+
 		@\header('Content-Type: text/plain; charset=utf-8');
 		$this->oActions->Logger()->Write('Pong', \MailSo\Log\Enumerations\Type::INFO, 'PING');
 		return 'Pong';
@@ -869,6 +875,8 @@ class ServiceActions
 	 */
 	public function ServiceInfo()
 	{
+		$this->oHttp->ServerNoCache();
+
 		if ($this->oActions->IsAdminLoggined(false))
 		{
 			@\header('Content-Type: text/html; charset=utf-8');
@@ -881,6 +889,8 @@ class ServiceActions
 	 */
 	public function ServiceSso()
 	{
+		$this->oHttp->ServerNoCache();
+
 		$oException = null;
 		$oAccount = null;
 		$bLogout = true;
@@ -997,6 +1007,8 @@ class ServiceActions
 	 */
 	public function ServiceExternalLogin()
 	{
+		$this->oHttp->ServerNoCache();
+		
 		$oException = null;
 		$oAccount = null;
 		$bLogout = true;
@@ -1063,6 +1075,8 @@ class ServiceActions
 	 */
 	public function ServiceExternalSso()
 	{
+		$this->oHttp->ServerNoCache();
+
 		$sResult = '';
 		$bLogout = true;
 		$sKey = $this->oActions->Config()->Get('labs', 'external_sso_key', '');
@@ -1104,6 +1118,8 @@ class ServiceActions
 	 */
 	public function ServiceChange()
 	{
+		$this->oHttp->ServerNoCache();
+
 		$oAccount = $this->oActions->GetAccount();
 
 		if ($oAccount && $this->oActions->GetCapa(false, \RainLoop\Enumerations\Capa::ADDITIONAL_ACCOUNTS, $oAccount))
diff --git a/rainloop/v/0.0.0/app/localization/langs.yml b/rainloop/v/0.0.0/app/localization/langs.yml
index 6b71ebd02..3f95eb9b7 100644
--- a/rainloop/v/0.0.0/app/localization/langs.yml
+++ b/rainloop/v/0.0.0/app/localization/langs.yml
@@ -2,7 +2,7 @@
 Common:
     LANGS_NAMES:
         LANG_EN: English
-        LANG_EN_US: English (US)
+        LANG_EN_US: English
         LANG_EN_GB: English (UK)
         LANG_EN_UK: English (UK)
         LANG_EN_CA: English (Canadian)
diff --git a/rainloop/v/0.0.0/app/templates/Views/Admin/AdminSettingsGeneral.html b/rainloop/v/0.0.0/app/templates/Views/Admin/AdminSettingsGeneral.html
index ddd69856f..f1effa3f3 100644
--- a/rainloop/v/0.0.0/app/templates/Views/Admin/AdminSettingsGeneral.html
+++ b/rainloop/v/0.0.0/app/templates/Views/Admin/AdminSettingsGeneral.html
@@ -13,7 +13,7 @@
 			<div class="controls">
 				<div class="flag-selector">
 					<span class="flag-wrapper">
-						<span data-bind="css: 'flag flag-' + language()" style=""></span>
+						<span data-bind="css: 'flag flag-' + language().toLowerCase()" style=""></span>
 					</span>
 					<span class="flag-name" tabindex="0" data-bind="text: languageFullName, click: selectLanguage, onSpace: selectLanguage, onEnter: selectLanguage"></span>
 					&nbsp;&nbsp;
diff --git a/rainloop/v/0.0.0/app/templates/Views/Common/PopupsLanguages.html b/rainloop/v/0.0.0/app/templates/Views/Common/PopupsLanguages.html
index 898d563b0..4e365ef2d 100644
--- a/rainloop/v/0.0.0/app/templates/Views/Common/PopupsLanguages.html
+++ b/rainloop/v/0.0.0/app/templates/Views/Common/PopupsLanguages.html
@@ -11,7 +11,7 @@
 				<label class="lang-item" data-tooltip-i18n="off" data-tooltip-join="right" data-bind="click: function () { $root.changeLanguage(key); }, css: {'selected': selected, 'user': user},
 					tooltip: function () { return $root.languageTooltipName(key); }">
 					<span class="flag-wrapper">
-						<span data-bind="css: 'flag flag-' + key" style=""></span>
+						<span data-bind="css: 'flag flag-' + key.toLowerCase()" style=""></span>
 					</span>
 					<span class="lang-name" data-bind="text: fullName"></span>
 					<i class="icon-ok pull-right" style="color: green; margin-top: 3px;"
diff --git a/rainloop/v/0.0.0/app/templates/Views/User/SettingsGeneral.html b/rainloop/v/0.0.0/app/templates/Views/User/SettingsGeneral.html
index 61e08d2c0..041df2dc5 100644
--- a/rainloop/v/0.0.0/app/templates/Views/User/SettingsGeneral.html
+++ b/rainloop/v/0.0.0/app/templates/Views/User/SettingsGeneral.html
@@ -21,7 +21,7 @@
 			<div class="controls">
 				<div class="flag-selector">
 					<span class="flag-wrapper">
-						<span data-bind="css: 'flag flag-' + language()" style=""></span>
+						<span data-bind="css: 'flag flag-' + language().toLowerCase()" style=""></span>
 					</span>
 					<span class="flag-name" tabindex="0" data-bind="text: languageFullName, click: selectLanguage, onSpace: selectLanguage, onEnter: selectLanguage"></span>
 					&nbsp;&nbsp;