@@ -76,6 +76,9 @@ public List<object> XTimeTicks
 
                 if (firstItem is DateTime)
                 {
+                    if(_x == null)
+                        _x = new List<object>();
+
                     _x.Clear();
                     foreach (var item in value)
                         _x.Add(((DateTime)item).ToString("yyyy-MM-ddTHH:mm:ss,ffffff"));
Original file line number	Diff line number	Diff line change
`@@ -76,6 +76,9 @@ public List<object> XTimeTicks`
`76`	`76`
`77`	`77`	`if (firstItem is DateTime)`
`78`	`78`	`{`
	`79`	`+ if(_x == null)`
	`80`	`+ _x = new List<object>();`
	`81`	`+`
`79`	`82`	`_x.Clear();`
`80`	`83`	`foreach (var item in value)`
`81`	`84`	`_x.Add(((DateTime)item).ToString("yyyy-MM-ddTHH:mm:ss,ffffff"));`