What are common causes of an 'invalid payload' error in Directus?

Common causes include: 1) Incorrect data types (e.g., sending a string when a number is expected). 2) Missing required fields. 3) Data exceeding the maximum allowed length. 4) Invalid characters in a field. 5) Incorrect format for specific fields (e.g., date format). 6) Mismatched casing for field names.