Describe the bug
BlurStyle.outer causes the app to crash on real device

To Reproduce
Steps to reproduce the behavior:

1. use the main.dart file in the example folder
2. Run the app on real device (N.B the app works fine on Genymotion emulator).
3. When clicking on the icon to change the BlurStyle and it is on the BlurStyle.outer, the app crashes

From Reference.md:

  service.open({

      id : "local.net/s+T6Ad2s2TC2A"

  }).then( object => {

  })
  .catch( error => { ... });

Object will be created with an autogenerated id, if no id argument is provided. Optionally, a "prefix" can be passed

例如下图所示现象,这些图分别用谷歌浏览器和小米浏览器打开，均有缺失现象

博客地址分别是：

• ourfor.top
• [www.sivan0222.cn](htt