X_UI_FORM_PATH_INVALID

a form control name is not a usable field path

two conditions, one code. A control name — or a fields entry handed to formBinding — the path grammar cannot read (items.0.price where items[0].price was meant, or items[]); or two controls describing different shapes for one path, user beside user.name. Refused at DECLARATION, which is the only place either can be caught: a name attribute and a schema issue path are the SAME string, so a path no issue can ever equal is a field whose server errors land at the top of the form forever — indistinguishable from an app with no bug at all. The conflict half is refused rather than resolved because either answer silently drops one control's value, and the value dropped is something the user typed

rename it to a segment, then .segment or [index] — "title", "items[0].price", never "items.0.price" or "items[]". For the conflict, rename one of the two controls: a path segment holds a value or a container, never both