try fix

package.json

 {
     "name": "react-ag-qeditor",
-    "version": "1.0.74",
+    "version": "1.0.75",
     "description": "WYSIWYG html editor",
     "author": "atma",
     "license": "MIT",

src/extensions/DragAndDrop.js

@@ -17,7 +17,7 @@ const DragAndDrop = Extension.create({
     addProseMirrorPlugins() {
         return [
             new Plugin({
-                key: new PluginKey('drop'),
+                key: new PluginKey('customDragAndDrop'),
                 props: {
                     handleDOMEvents: {
                         async paste (view, event) {