After following the tutorial at https://learn.getgrav.org/forms/forms/example-form I keep getting a "RuntimeException (400) Display page not found. " error
I have a ‘thankyou’ folder in user/pages and when going to /thankyou I can see that page like any other page on the site.
Any ideas to what might be going wrong here?
The e-mail from the form does get sent by the way, so that part apparently works 
On your form “process:” maybee try removing - display: thankyou and see if it works?
I think in order for the thank you page to display it has to exist. So you need to make a separate thankyou.md inside a folder inside the page. Let me know if that was it.
Also try going to the admin pannel and making sure the thank you page parent is set to the form.
Here’s a pic of what structure I’ve got, which works.
Just a guess, but maybe you named your page inside /thankyou as the tutorial suggest: formdata.md. Thus, grav is looking for a page template named formdata.html.twig
You can either rename your file or specify a template: yourtemplate in the frontmatter
@davidalanbruce yeah I already have that page so it exists, although a bit different from what you named it. My current folder structure looks like this:
06.contact
–form.md
thankyou
– form.md
Ah fixed it: “Parent” was set to root. Changed that to the specific form and now it works!
This one seems very tricky to me!
I’ve had the same problem, same Folder Structure, but nothing seemed to solve it. Just after I modified the Folder Structure via Admin Plugin (Set Parent to another page and back again) it works for me. Maybe this helps someone else before going mad. 
Was this with the latest version of the Form plugin?
Yes, I’ve updated everything before. Could it be just a cause of caching? Inwill have an eye on this the next time.
