EditorArea.xml file giving:MalformedByteSequenceException: Invalid byte 2 of 2-byte UTF-8 sequence

Adding editorArea for customizing the custom component by cmsCockpit. It will not display editorArea in cmscockpit Giving error in console:"MalformedByteSequenceException: Invalid byte 2 of 2-byte UTF-8 sequence". Why EditorArea is not displaying in cmscockpit when my editorArea.xml file is correct