"The property '[object Object]' does not exist on type 'SP.Data.StudentsListItem'. Make sure to only use property names that are defined by the type."

 Error: "The property '[object Object]' does not exist on type 'SP.Data.StudentsListItem'. Make sure to only use property names that are defined by the type."

Cause: The above issue may come if we are trying to add/update the field name (like 'Student_x0020_Roll') but that field is not available in the Students SharePooint list. OR the field ('Student_x0020_Roll') is look up from some other list but we are tryng to updated as text field.

ex.

var data= {
__metadata:{

type:'SP.Data.StudentsListItem' //ListItemEntityTypeFullName for list Student

}
'Title':'Ramesh',
'Student_x0020_Roll':'102510',
};

Solution:
If required Field (like 'Student_x0020_Roll') is not available and required then we need to create it or if not required then we can removed  from saving (from data object).

If the required Field (like 'Student_x0020_Roll') is lookup then we need to update it as we are updating for lookup field.

ex.

var data= {
__metadata:{

type:'SP.Data.StudentsListItem' //ListItemEntityTypeFullName for list Student

}
'Title':'Ramesh',
'Student_x0020_RollId':5,
};