Cannot Display Error Mark for Field Inside Tab

[protocyber]

I try to return the following error message after submitting form data:

{
    success: false,
    msg: 'Please re-enter invalid data.',
    errors: {testField: 'Test message'}
}

testField is the name of field which is located inside tab.

If I replace testField with another field-name located outside the tab, the invalid mark is displayed properly.

How to solve this problem?? Thank you very much.

UPDATE: Here is the code of the form panel:

Ext.define('App.view.siswa.FormTambah', {
    extend: 'App.widget.FormTambah',
    alias : 'widget.edu-formTambahSiswa',


    title : 'Input Data Siswa',
    width: 700,
    height: 450,


    initComponent: function() {
        this.items = [{
            xtype: 'form',
            url: baseUrl + 'Siswa/tambah.html',
            bodyPadding: 20,
            layout: {
                type: 'hbox',
                align: 'stretch'
            },
            items: [{
                xtype: 'container',
                width: 128,
                items: [{
                    xtype: 'container',
                    style: 'text-align: center',
                    html: '<img src="images/icon_128/emblem-person.png" width="128" height="128"/>'
                }]
            }, {
                xtype: 'container',
                layout: {
                    type: 'vbox',
                    align: 'stretch'
                },
                flex: 1,
                margins: '0 0 0 20',
                items: [{
                    xtype: 'container',
                    layout: 'anchor',
                    margins: '0 0 23 0',
                    defaults: {
                        xtype: 'textfield',
                        labelWidth: 135,
                        labelSeparator: '',
                        allowBlank: false
                    },
                    items: [{
                        xtype: 'numberfield',
                        name : 'nomorInduk',
                        fieldLabel: 'Nomor Induk',
                        hideTrigger: true,
                        allowDecimals: false,
                        minValue: 0
                    }, {
                        name : 'nama',
                        fieldLabel: 'Nama',
                        width: 454
                    }, {
                        xtype: 'edu-comboBoxKelas',
                        name : 'kelas',
                        fieldLabel: 'Kelas'
                    }]
                }, {
                    xtype: 'tabpanel',
                    flex: 1,
                    bodyStyle: 'padding-top: 10px',
                    border: false,
                    plain: true,
                    items: [{
                        xtype: 'container',
                        title: 'Data Siswa',
                        layout: 'anchor',
                        defaults: {
                            xtype: 'textfield',
                            labelWidth: 135,
                            labelSeparator: ''
                        },
                        items: [{
                            xtype: 'numberfield',
                            name : 'testField',
                            fieldLabel: 'NISN',
                            hideTrigger: true,
                            allowDecimals: false,
                            minValue: 0
                        }, {
                            xtype: 'filefield',
                            name: 'foto',
                            fieldLabel: 'Foto',
                            iconCls: 'upload16',
                            buttonOnly: true,
                            buttonText: 'Pilih Foto...',
                            buttonConfig: {
                                iconCls: 'upload16'
                            }
                        }]
                    }, {
                        xtype: 'container',
                        title: 'Data Keluarga',
                        layout: 'anchor',
                        autoScroll: true,
                        defaults: {
                            xtype: 'textfield',
                            labelWidth: 135,
                            labelSeparator: ''
                        },
                        items: [{
                            xtype: 'fieldcontainer',
                            fieldLabel: 'Anak Ke',
                            layout: 'hbox',
                            defaults: {
                                xtype: 'numberfield',
                                allowDecimals: false,
                                labelSeparator: '',
                                labelWidth: 100
                            },
                            items: [{
                                name: 'anakKe',
                                minValue: 1,
                                width: 50,
                                margins: '0 35 0 0'
                            }}]
                        }, {
                            xtype: 'fieldcontainer',
                            fieldLabel: 'Data Ayah',
                            defaults: {
                                xtype: 'textfield',
                                labelSeparator: '',
                                labelWidth: 80
                            },
                            items: [{
                                name: 'namaAyah',
                                fieldLabel: 'Nama Ayah',
                                width: 314
                            }]
                        }, {
                            xtype: 'fieldcontainer',
                            fieldLabel: 'Data Ibu',
                            defaults: {
                                xtype: 'textfield',
                                labelSeparator: '',
                                labelWidth: 80
                            },
                            items: [{
                                name: 'namaIbu',
                                fieldLabel: 'Nama Ibu',
                                width: 314
                            }]
                        }]
                    }]
                }]
            }]
        }];


        this.callParent(arguments);
    }, // initComponent
    
    onShow: function(){
        this.down('tabpanel').setActiveTab(0);
        this.callParent(arguments);
    }
});

[mitchellsimoens]

Is the testfield registered with the basic form?

[protocyber]

Is the testfield registered with the basic form?

Yes, of course. The testField is inside the tab panel. And the tab panel is inside form panel.

I've updated my previous post. Please see the form panel's code in my post above.

[protocyber]

Any solution??