422
Unprocessable content
What it means
The request arrived in a format the server understands, but the values failed its validation.
Common causes
- A required field is empty or too long
- A date or number outside the allowed range
- A stale form token
How to fix it
- Read the error message on the page; it usually names the field.
- Reload the form so it gets a fresh token, then fill it again.
- Remove special characters from names and check the date format.
- Report it to the site if a valid entry is rejected.