diff --git a/application/Espo/Core/Utils/Json.php b/application/Espo/Core/Utils/Json.php
index 4b1c6d213d..ebcabb36e5 100644
--- a/application/Espo/Core/Utils/Json.php
+++ b/application/Espo/Core/Utils/Json.php
@@ -18,95 +18,101 @@
  *
  * You should have received a copy of the GNU General Public License
  * along with EspoCRM. If not, see http://www.gnu.org/licenses/.
- ************************************************************************/ 
+ ************************************************************************/
 
 namespace Espo\Core\Utils;
 
 class Json
 {
 	/**
-     * JSON encode a string
-     *
-     * @param string $value
-     * @param int $options Default 0
-     * @param int $depth Default 512
-     * @return string
-     */
+	 * JSON encode a string
+	 *
+	 * @param string $value
+	 * @param int $options Default 0
+	 * @param int $depth Default 512
+	 * @return string
+	 */
 	public static function encode($value, $options = 0, $depth = 512)
 	{
 		if (version_compare(phpversion(), '5.5.0', '>=')) {
-	        $json = json_encode($value, $options, $depth);
-	    }
-	    elseif (version_compare(phpversion(), '5.3.0', '>=')) {
+			$json = json_encode($value, $options, $depth);
+		}
+		elseif (version_compare(phpversion(), '5.3.0', '>=')) {
 			/*Check if options are supported for this version of PHP*/
-	    	if (is_int($options)) {
-            	$json = json_encode($value, $options);
-	    	}
+			if (is_int($options)) {
+				$json = json_encode($value, $options);
+			}
 			else {
 				$json = json_encode($value);
 			}
-	    }
-	    else {
-	        $json = json_encode($value);
-	    }
-
-		if ($json===null) {
-			$GLOBALS['log']->error('Value cannot be decoded to JSON - '.print_r($value, true));
+		}
+		else {
+			$json = json_encode($value);
 		}
 
-        return $json;		
+		$error = self::getLastError();
+		if ($json === null || $error) {
+			$GLOBALS['log']->error('Json::encode():' . $error . ' - ' . print_r($value, true));
+		}
+
+		return $json;
 	}
 
 	/**
-     * JSON decode a string (Fixed problem with "\")
-     *
-     * @param string $json
-     * @param bool $assoc Default false
-     * @param int $depth Default 512
-     * @param int $options Default 0
-     * @return object
-     */
+	 * JSON decode a string (Fixed problem with "\")
+	 *
+	 * @param string $json
+	 * @param bool $assoc Default false
+	 * @param int $depth Default 512
+	 * @param int $options Default 0
+	 * @return object
+	 */
 	public static function decode($json, $assoc = false, $depth = 512, $options = 0)
 	{
 		if (is_array($json)) {
-			$GLOBALS['log']->warning('JSON:decode() - JSON cannot be decoded - '.$json);
+			$GLOBALS['log']->warning('Json::decode() - JSON cannot be decoded - '.$json);
 			return false;
 		}
 
-	    if(version_compare(phpversion(), '5.4.0', '>=')) {
-	        $json = json_decode($json, $assoc, $depth, $options);
-	    }
-	    elseif(version_compare(phpversion(), '5.3.0', '>=')) {
-	        $json = json_decode($json, $assoc, $depth);
-	    }
-	    else {
-	        $json = json_decode($json, $assoc);
-	    }
+		if(version_compare(phpversion(), '5.4.0', '>=')) {
+			$json = json_decode($json, $assoc, $depth, $options);
+		}
+		elseif(version_compare(phpversion(), '5.3.0', '>=')) {
+			$json = json_decode($json, $assoc, $depth);
+		}
+		else {
+			$json = json_decode($json, $assoc);
+		}
 
-	    return $json;
-	}
+		$error = self::getLastError();
+		if ($json === null || $error) {
+			$GLOBALS['log']->error('Json::decode():' . $error);
+		}
 
-
-    /**
-     * Check if the string is JSON
-     *
-     * @param string $json
-     * @return bool
-     */
-	public static function isJSON($json)
-	{  
-		if ($json === '[]' || $json === '{}') {     
-			return true;
-		} else if (is_array($json)) {  	   	
-        	return false;
-		}                   	    
-		
-	    return static::decode($json) != null;
+		return $json;
 	}
 
 
 	/**
-    * Get an array data (if JSON convert to array)
+	 * Check if the string is JSON
+	 *
+	 * @param string $json
+	 * @return bool
+	 */
+	public static function isJSON($json)
+	{
+		if ($json === '[]' || $json === '{}') {
+			return true;
+		} else if (is_array($json)) {
+			return false;
+		}
+
+		return static::decode($json) != null;
+	}
+
+
+	/**
+	* Get an array data (if JSON convert to array)
 	*
 	* @param mixed $data - can be JSON, array
 	*
@@ -115,14 +121,64 @@ class Json
 	public static function getArrayData($data)
 	{
 		if (is_array($data)) {
-        	return $data;
+			return $data;
 		}
 		else if (static::isJSON($data)) {
-        	return static::decode($data, true);
-        }
+			return static::decode($data, true);
+		}
 
 		return array();
 	}
 
+
+	protected static function getLastError($error = null)
+	{
+		if (!isset($error)) {
+			$error = json_last_error();
+		}
+
+		switch ($error) {
+			case JSON_ERROR_NONE:
+				return false;
+			break;
+
+			case JSON_ERROR_DEPTH:
+				return 'The maximum stack depth has been exceeded';
+			break;
+
+			case JSON_ERROR_STATE_MISMATCH:
+				return 'Invalid or malformed JSON';
+			break;
+
+			case JSON_ERROR_CTRL_CHAR:
+				return 'Control character error, possibly incorrectly encoded';
+			break;
+
+			case JSON_ERROR_SYNTAX:
+				return 'Syntax error, malformed JSON';
+			break;
+
+			case JSON_ERROR_UTF8:
+				return 'Malformed UTF-8 characters, possibly incorrectly encoded';
+			break;
+
+			/* Only for PHP 5.5.0
+			case JSON_ERROR_RECURSION:
+				return 'One or more recursive references in the value to be encoded';
+			break;
+			case JSON_ERROR_INF_OR_NAN:
+				return 'One or more NAN or INF values in the value to be encoded';
+			break;
+			case JSON_ERROR_UNSUPPORTED_TYPE:
+				return 'A value of a type that cannot be encoded was given';
+			break;
+			*/
+
+			default:
+				return 'Unknown error';
+			break;
+		  }
+	}
+
 }
 
diff --git a/tests/Espo/Core/Utils/JsonTest.php b/tests/Espo/Core/Utils/JsonTest.php
index d15a9c6ed4..19f9a64ee6 100644
--- a/tests/Espo/Core/Utils/JsonTest.php
+++ b/tests/Espo/Core/Utils/JsonTest.php
@@ -6,38 +6,48 @@ use Espo\Core\Utils\Json;
 
 class JsonTest extends \PHPUnit_Framework_TestCase
 {
-	function testEncode()
+	protected function setUp()
+    {
+		$GLOBALS['log'] = $this->getMockBuilder('\Espo\Core\Utils\Log')->disableOriginalConstructor()->getMock();
+    }
+
+    protected function tearDown()
+    {
+        $this->object = NULL;
+    }
+
+	public function testEncode()
 	{
 		$testVal= array('testOption'=>'Test');
 		$this->assertEquals(json_encode($testVal), Json::encode($testVal));
 	}
 
-	function testDecode()
+	public function testDecode()
 	{
 		$testVal= array('testOption'=>'Test');
-		$this->assertEquals($testVal, Json::decode(json_encode($testVal), true));        
+		$this->assertEquals($testVal, Json::decode(json_encode($testVal), true));
 
 		$test= '{"folder":"data\/logs"}';
-        $this->assertEquals('data/logs', Json::decode($test)->folder);  	     
+		$this->assertEquals('data/logs', Json::decode($test)->folder);
 	}
 
-	function testIsJSON()
+	public function testIsJSON()
 	{
-		$this->assertTrue(Json::isJSON('{"database":{"driver":"pdo_mysql","host":"localhost"},"devMode":true}'));  		
-		
-	    $this->assertTrue(Json::isJSON('[]'));
-		
-	    $this->assertTrue(Json::isJSON('{}'));
-		
-	    $this->assertTrue(Json::isJSON('true'));
-		
+		$this->assertTrue(Json::isJSON('{"database":{"driver":"pdo_mysql","host":"localhost"},"devMode":true}'));
+
+		$this->assertTrue(Json::isJSON('[]'));
+
+		$this->assertTrue(Json::isJSON('{}'));
+
+		$this->assertTrue(Json::isJSON('true'));
+
 		$this->assertFalse(Json::isJSON('some string'));
-		
+
 		$this->assertTrue(Json::isJSON(true));
 		$this->assertEquals('true', json_encode(true));
-		
+
 		$this->assertFalse(Json::isJSON(false));
-		$this->assertEquals('false', json_encode(false)); 	   
+		$this->assertEquals('false', json_encode(false));
 	}