Affects Version/s: 7.0.X, Master
Stept to reproduce:
1) Create a new Form (called 'form1')
2) In form1 place a Single Selection input (named 'radio1') and allow 2 options ('option1' and 'option2'). This input doesn't need to be a required field (therefore not marked with asterisk).
3) Place a Form portlet on your test site ('Welcome') and select form1 to be displayed.
If you browse with IE11, submitting the form is unsuccessful unless option2 is selected.
If it is submitted with option1 or no selection, the following error message is displayed: "The selected form no longer exists."
The behavior is only reproducible with browser IE11. Not reproducible on Edge, Firefox or Chrome.
To be able submitting this form with any settings described above, as it already works on other browsers.