diff --git a/application/controllers/admin/tokens.php b/application/controllers/admin/tokens.php
index b36b3417f13..5a07f22e580 100644
--- a/application/controllers/admin/tokens.php
+++ b/application/controllers/admin/tokens.php
@@ -411,11 +411,10 @@ public function editMultiple()
 
                 // Email
                 if (trim(Yii::app()->request->getPost('email', 'lskeep')) != 'lskeep') {
-                    $isValid = preg_match('/^([a-zA-Z0-9.!#$%&’*+\/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+))(,([a-zA-Z0-9.!#$%&’*+\/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)))*$/', Yii::app()->request->getPost('email'));
-                    if ($isValid) {
-                        $aData['email'] = Yii::app()->request->getPost('email');
+                    if (trim(Yii::app()->request->getPost('email')) == '') {
+                        $aData['email'] = null;
                     } else {
-                        $aData['email'] = 'lskeep';
+                        $aData['email'] = trim(Yii::app()->request->getPost('email'));
                     }
                 }
 
@@ -1950,7 +1949,6 @@ public function import($iSurveyId)
         $aData['title_bar']['title'] = $survey->currentLanguageSettings->surveyls_title." (".gT("ID").":".$iSurveyId.")";
         $aData['sidemenu']["token_menu"] = true;
         $aData['token_bar']['closebutton']['url'] = 'admin/tokens/sa/index/surveyid/'.$iSurveyId;
-        $aData['topBar']['showSaveButton'] = true;
         $aData['topBar']['closeButtonUrl'] = Yii::app()->createUrl('admin/tokens/sa/index/surveyid/'.$iSurveyId);
         App()->getClientScript()->registerScriptFile(App()->getConfig('adminscripts').'tokensimport.js');
         $aEncodings = aEncodingsArray();
diff --git a/application/core/LSSodium.php b/application/core/LSSodium.php
index 1013bed928d..75cd8f17fa8 100644
--- a/application/core/LSSodium.php
+++ b/application/core/LSSodium.php
@@ -101,15 +101,19 @@ public function encrypt($sDataToEncrypt){
 	 * 
 	 * Decrypt encrypted string.
 	 * @param string $sEncryptedString Encrypted string to decrypt
-	 * @param bool $bReturnFalseIfError false by default. If TRUE, return false in case of error (bad decryption). Else, return given $encryptedInput value
-	 * @return string Return decrypted value (string or unsezialized object) if suceeded. Return FALSE if an error occurs (bad password/salt given) or inpyt encryptedString
+	 * @param bool $bReturnInputIfError FALSE by default. If TRUE, return given $sEncryptedString in case of error (bad input/password/salt). Else, throw exception in case of error (bad input/password/salt).
+	 * @return string Return decrypted value (string or unsezialized object) if suceeded. Throw exception if an error occurs (bad input/password/salt) or given $sEncryptedString
 	 */
-	public function decrypt($sEncryptedString, $bReturnFalseIfError=false){ 	
+	public function decrypt($sEncryptedString, $bReturnInputIfError=false){ 	
         if ($this->bLibraryExists === true){
             if (!empty($sEncryptedString) && $sEncryptedString != 'null'){
                 $plaintext = ParagonIE_Sodium_Compat::crypto_sign_open(base64_decode($sEncryptedString), $this->sEncryptionPublicKey);
                 if ($plaintext === false){
-                    throw new SodiumException(sprintf(gT("Wrong decryption key! Decryption key has changed since this data were last saved, so data can't be decrypted. Please consult our manual at %s.", 'unescaped'), 'https://manual.limesurvey.org/Data_encryption#Errors'));
+                    if ($bReturnInputIfError === false){
+                        throw new SodiumException(sprintf(gT("Wrong decryption key! Decryption key has changed since this data were last saved, so data can't be decrypted. Please consult our manual at %s.", 'unescaped'), 'https://manual.limesurvey.org/Data_encryption#Errors'));
+                    } else {
+                        return $sEncryptedString;
+                    }
                 } else {
                     return $plaintext;
                 }
diff --git a/application/models/LSActiveRecord.php b/application/models/LSActiveRecord.php
index 51412a8847c..aec8c578996 100644
--- a/application/models/LSActiveRecord.php
+++ b/application/models/LSActiveRecord.php
@@ -387,10 +387,13 @@ public function encrypt()
     /**
      * Encrypt values before saving to the database
      */
-    public function encryptSave($runValidation=false)
+    public function encryptSave($runValidation=true)
     {
         // run validation on attribute values before encryption take place, it is impossible to validate encrypted values
         if ($runValidation){
+            // decrypt attributes before validation, return input value if decryption failed (ie because of unencrypted value in encrypted field)
+            $this->decryptEncryptAttributes('decrypt', $bReturnInputIfError=true);
+            // validate attributes
             if(!$this->validate()) {
                 return false;
             }  
@@ -406,7 +409,7 @@ public function encryptSave($runValidation=false)
     /**
      * Encrypt/decrypt values
      */
-    public function decryptEncryptAttributes($action = 'decrypt')
+    public function decryptEncryptAttributes($action = 'decrypt', $bReturnInputIfError=false)
     {
         // load sodium library
         $sodium = Yii::app()->sodium;
@@ -416,13 +419,18 @@ public function decryptEncryptAttributes($action = 'decrypt')
             $aParticipantAttributes = CHtml::listData(ParticipantAttributeName::model()->findAll(array("select" => "attribute_id", "condition" => "encrypted = 'Y' and core_attribute <> 'Y'")), 'attribute_id', '');
             foreach ($aParticipantAttributes as $attribute => $value) {
                 if (array_key_exists($this->attribute_id, $aParticipantAttributes)) {
-                    $this->value = $sodium->$action($this->value);
+                    $this->value = $sodium->$action($this->value, $bReturnInputIfError);
                 }
             }
         } else {
             $attributes = $this->encryptAttributeValues($this->attributes, true, false);
             foreach ($attributes as $key => $attribute) {
-                $this->$key = $sodium->$action($attribute);
+                // check if the attribute should be decrypted and can be decrypted (maybe plaintexts in crypted fields)
+                if ($action == 'decrypt' && strlen(base64_decode($attribute)) < 64) {
+                    // attribute is not a valid base64 encoded value and can not be decrypted
+                } else {
+                    $this->$key = $sodium->$action($attribute, $bReturnInputIfError);
+                }
             }
         }
     }
diff --git a/tests/unit/models/EncryptAttributesTest.php b/tests/unit/models/EncryptAttributesTest.php
index 6ed3354233c..d55db8c9293 100644
--- a/tests/unit/models/EncryptAttributesTest.php
+++ b/tests/unit/models/EncryptAttributesTest.php
@@ -26,6 +26,12 @@ public static function setupBeforeClass()
      */
     public function testToken()
     {
+        function generateRandomString($length = 10) {
+            return substr(str_shuffle(str_repeat($x='0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ', ceil($length/strlen($x)) )),1,$length);
+        }
+        
+        $teststring = generateRandomString(128);
+
         // Get our token.
         $tokens = \TokenDynamic::model(self::$surveyId)->findAll();
         $this->assertNotEmpty($tokens);
@@ -33,7 +39,7 @@ public function testToken()
         $token = $tokens[0];
 
         // Change lastname.
-        $token->lastname = 'last';
+        $token->lastname = $teststring;
         $token->encryptSave();
 
         // Load token and decrypt.
@@ -41,13 +47,13 @@ public function testToken()
         $this->assertCount(1, $tokens);
         $token = $tokens[0];
         $token->decrypt();
-        $this->assertEquals('last', $token->lastname);
+        $this->assertEquals($teststring, $token->lastname);
 
         // Test the omitting decrypt() works.
         $tokens = \TokenDynamic::model(self::$surveyId)->findAll();
         $this->assertCount(1, $tokens);
         $token = $tokens[0];
-        $this->assertNotEquals('last', $token->lastname);
+        $this->assertNotEquals($teststring, $token->lastname);
     }
 
     /**