I have created a quite complexe multistep ajax form.
It works pretty well except when some mandatory fields are missing.
Actually, the form is returned correctly with all the errors highlighted. But when I try to submit it again, it is not an ajax form anymore and it returns a json array instead of the next step.
May be it's because at some step, the form id changes:
For example, let's say the form id is "wizard", at some point in the multistep process it becomes "wizard--5".
Any idea why ?