extjs7 selectfield异常 Uncaught TypeError: Cannot read property 'hasPendingLoad' of null

 {
    xtype: 'selectfield', label: '支持类型', bind: {store: '{types}', value: '{types}'},
    multiSelect: true
}

data: {
	types: null
},
stores: {
        types: {
            data: [...]
        }
    }