Hello,

I try to use the form builder in Odoo13. Also tried on runbot, same behavior.
Just wondering if this is normal behavior or not.

Situation:
Make a form, related to model opportunity.
Add existing field "Main Attachment"
Try to submit.

It won't work, you get error message: An error has occured, the form has not been sent.

When you do the same and relate your form to for example task, it works like expected.

Am I missing something that attachments are not allowed in opportunities / leads ???