Index: lams_central/web/ckeditor/plugins/image2/dialogs/image2.js
===================================================================
diff -u -r62a52d851ecb5878433ca8ecd5ef422375619f47 -r3804872c0e7df924187104b3e3883e478e7db896
--- lams_central/web/ckeditor/plugins/image2/dialogs/image2.js	(.../image2.js)	(revision 62a52d851ecb5878433ca8ecd5ef422375619f47)
+++ lams_central/web/ckeditor/plugins/image2/dialogs/image2.js	(.../image2.js)	(revision 3804872c0e7df924187104b3e3883e478e7db896)
@@ -455,7 +455,7 @@
                         	var oldClasses = widget.getClasses();
                         	
                         	//add new classes
-                        	var userEnteredClasses = this.getValue().split(',');
+                        	var userEnteredClasses = this.getValue().split(',').filter(x => x);
                         	for (var i = 0; i < userEnteredClasses.length; i++) {
                         		var userEnteredClass = userEnteredClasses[i];
                         	    if (!widget.hasClass(userEnteredClass)) {