获取UIContext报错1300002如何解决

import window from '@ohos.window'; 
import hilog from '@ohos.hilog'; 
import UIAbility from '@ohos.app.ability.UIAbility'; 
import { BusinessError } from '@ohos.base'; 
 
export default class EntryAbility extends UIAbility { 
  onWindowStageCreate(windowStage: window.WindowStage) { 
    hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onWindowStageCreate'); 
    windowStage.loadContent('pages/Index', (err, data) => { 
      if (err.code) { 
        hilog.error(0x0000, 'testTag', 'Failed to load the content. Cause: %{public}s', JSON.stringify(err) ?? ''); 
        return; 
      } 
      windowStage.getMainWindow((err: BusinessError, data) => { 
        let errCode: number = err.code; 
        if (errCode) { 
          console.error('Failed to obtain the main window.Cause:' + JSON.stringify(err)) 
        } 
        let uiContext = data.getUIContext(); 
        console.log(JSON.stringify(uiContext)) 
      }) 
      hilog.info(0x0000, 'testTag', 'Succeeded in loading the content. Data: %{public}s', JSON.stringify(data) ?? ''); 
    }); 
  } 
};