Update

public/admin/plugins/tmce/cpBlock/plugin.js

@@ -0,0 +1,18 @@
+tinymce.PluginManager.add('cpBlock', function(editor, url) {
+
+    editor.addButton('cpBlock', {
+        image: 'data:image/png;base64,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',
+        tooltip: 'Blocks',
+        onclick: open_Browser
+    });
+
+    function open_Browser() {
+
+        editor.windowManager.open({
+            title: 'Select Block',
+            width: 500,
+            height: 400,
+            url: '/cp/tmce/plugin/block'
+        });
+    }
+});