Golden Layout 2.6版本状态保存失败问题求助

我在Angular项目里使用Golden Layout 2.6版本时，套用了官方文档中针对1.5.9以下版本的状态保存与加载代码：

myLayout.on( 'stateChanged', function(){
    var state = JSON.stringify( myLayout.toConfig() );
    localStorage.setItem( 'savedState', state );
});

var myLayout,
    savedState = localStorage.getItem( 'savedState' );

if( savedState !== null ) {
    myLayout = new GoldenLayout( JSON.parse( savedState ) );
} else {
    myLayout = new GoldenLayout( config );
} 

运行后出现以下错误：

app.routes.ts:9 ERROR TypeError: value.trimStart is not a function
    at splitStringAtFirstNonNumericChar (utils.js:12:17)
    at parseSize (config.js:856:7)
    at Object.resolveSize (config.js:62:14)
    at Object.resolve (config.js:232:20)
    at Object.resolve (config.js:19:32)
    at Object.resolve (config.js:542:33)
    at Object.resolve (config.js:716:30)
    at GoldenLayout.init (layout-manager.js:251:42)
    at GoldenLayout.init (virtual-layout.js:92:11)
    at _LayoutComponent.ngAfterViewInit (layout.component.ts:53:23)

我找不到可行的解决办法，怀疑是Golden Layout项目维护不到位导致的问题。另外我注意到React的flex layout在状态保存这块表现正常，有可复现该错误的最小代码示例。

内容的提问来源于stack exchange，提问作者Victor Martinez