Re: Adaptive Form - 'File Attachment' component leads to 'Encountered an internal error while submitting the form' on submit

You need to submit to an HTTPS end point.

On your local, enable HTTPS using self signed certificates. You can download the certificates from here and also watch the video on how to enable HTTPS on your local: https://experienceleague.adobe.com/docs/experience-manager-learn/foundation/security/use-the-ssl-wizard.html?lang=en

Once HTTPS is enabled, you should be able to submit the form.