Hello, i did same things in this tutorial Creating Drag and Drop UI | Unreal Engine Documentation
But i have a problem with on drop. When i drop the widget, widget dissappears.
Can someone please help me ? 
Show us your script for onDrop.
I posted.
You’re not getting AccessNone errors with this? Nothing in the log?
Also, is there any reason why you’re not using Payload for this?
No i don’t get any error.
No reason.I don’t know how to use it, What’s that for?
Can you put a print string after Cast Failed - I might be wrong but I feel your widget gets garbage collected.
I put print string after cast failed. But it didn’t call it . And i also put print string after on drop. Also didn’t call it.
Instead of plugging self into widget reference, plug it into Payload - that’s the default way the DragDrop operation holds onto the dragged widget’s reference.
When you drop it, drag a wire from Operation, get Payload → Cast directly to your widget, add it to viewport.
And i also put print string after on
drop
So hold on, your drop never gets called?
Yes my drop never gets called
No, no, just plug in Self into Payload and Drag Visual, not need to create another widget.
still doesn’t work. I think the problem is on Drop is never getting called.
Yup, definitely, regardless of everything we talked about, the drop should work.
So, is the widget that you’re dropping into set to Visible?
yes it is visible.
Is the widget you’re dropping on different from the widget you drag from?