I want to edit Default NewForm.aspx to add JS to it with Script Editor but I can´t do it because when I clic on it I get error: enter image description here

enter image description here

Why I can´t edit it? It always throw me that error so I can access to add Script Editor. Regards

  • Do you have any custom code in the new form ? Sep 5, 2017 at 21:50
  • My site have custom Layout , but about list I just create it, but I don´t modified nothing of code there because I can´t access it @M.Qassas
    – Ledwing
    Sep 5, 2017 at 21:51
  • Could you try the same functionality to another list? Sep 5, 2017 at 22:00
  • I create a new list and I added to WebPage but I get same result when trying to access to NewForm @M.Qassas
    – Ledwing
    Sep 5, 2017 at 22:05
  • Go to site content > click on your list > From the above ribbon try to use the form web part from this place! Sep 5, 2017 at 22:11

1 Answer 1


The unexpected error is an ambiguous error, But what I think you are using the New experiences for lists and the Form Web Parts is only available in the Classic experiences

So try to do the following:

  • Go to site content > open your list.
  • Go to list Setting > Advanced Setting.
  • Scroll down to List experience.

enter image description here

  • If the New Experience is checked so you will not be able to use Form Web Parts So Check Classic Experience to can open your forms in edit mode.

See also


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