Getting FieldError Unknown field(s)

Using Django Mystery Errors
2

It’s a Python syntax oddity. You need to either have:
'fields': ('contactos_masinfo',)

(notice the comma after the field name)

or you need to specify it as a list and not a tuple:
'fields': ['contactos_masinfo']

See Built-in Types — Python 3.12.0 documentation and
5. Data Structures — Python 3.12.0 documentation
(among other references.)