GO JS Undo Showing Error

Salaamun Alekum

While I Am Using GOJS Undo Operation Using Command Of My Code

diag.commandHandler.undo();

It Is Showing Me Following Mentioned Error In Console Of Browser

property set error: Error: Picture.element must be an instance of
Image, Canvas, or Video.

And After Using Undo When I Use Redo diag.commandHandler.redo(); Function
Then Nodes Data Array diagram.model.nodeDataArray; Gives Null

Can Anyone Identify What Could Be The Root Cause

Thank You

Greetings. And Happy Thanksgiving for those of us who are celebrating that today.

The error message is an error in the Picture.element property setter, which I have fixed in a beta release of 1.5.14: http://gojs.net/beta. Please try that to see if the error does not occur.

As far as your Model.nodeDataArray being set to null, that is very surprising – I cannot explain that. Maybe it won’t happen once this undo/redo problem is fixed. But if it does, we can look into it if you give us a way to reproduce that problem. Does your code ever set Model.nodeDataArray to any value?

Salaamun Alekum
And Greetings And Salutations And May Bless You In This Thanksgiving In Shah Allah [Smile]
Thank You Mr. Walter This Definitely Would Be Helpful
This Was Creating A Serious Issue In Our App We Were Thinking To Implement Our Own Manual Clipboard And Undo Redo Manager Today
I Shall Forward This To Our Seniors In Morning This Good News Will Definitely Resolve All The Issues In Shah Allah
I Am Really Honored And Thankful Of Your For Such A Nice Support And Kindness
Thank You So Much
[Smile]

Salaamun Alekum
Thank You Mr. Walter Using Latest Beta Version From http://gojs.net/beta/release/go.js
Did Solved Our Issue Thank You So Much For Your Kind Support

Thank You Mr. Walter And GOJS And NWoods Team
[Smile] Salaam

Very nice demo. Thank you for reporting the bug. I am sorry that you had to deal with it.