If your lead form is showing a character limit of “0”, it likely means there’s a glitch in Meta’s form builder, not that the form is unusable.
However, yes if the character limit is truly set to 0, users won't be able to type a response, which will block submissions for any custom questions that require input.
1) Duplicate the Form Instead of Editing the Glitched One
Go to your existing form and click “Duplicate.”
Rebuild the question with the correct character limit (e.g. 255 for short answers or 500 for longer ones).
2) Use Pre-fill Options Where Possible
Stick to pre-filled fields like name, email, phone—Meta handles these reliably.
3) Switch from “Short Answer” to “Multiple Choice” (if possible)
If the question can be restructured, this avoids character limit issues entirely.
4) Don’t Publish the Campaign Until Fixed
If you publish with a 0-character limit on required fields, the form will be broken for users.