Error not visible when there is no "page" created

[white-ruud]

Describe the bug

Somehow a customer of ours got in the situation where there is no "page".
Via "Add existing fields" they were still able to add fields, but when trying to save, this of course doesn't work.
The form says "Couldn’t save form.", but no visual hint that the "page" is missing. Maybe make the cogwheel also turn red?

Steps to reproduce

1. Have somehow a form without a "page"
2. Add fields via "Add existing fields"
3. Save form
4. Error without visual hint where the error comes from

Form settings

• Multi-page form: No
• Submission Method: Ajax or Page Reload
• Client-side Validation: Yes or No
• Custom Form Templates: No

Craft CMS version

5.9.18

Plugin version

3.1.19

Multi-site?

No response

Additional context

No response