Ionic V4 Playing local video doesn't work any more

I used the following code to load and play locally downloaded videos when Ionic V4 beta came out.

It stopped working with the latest final release.

No JS or native errors appear.

Any ideas?

const byteArray = await this.file.readAsArrayBuffer(basePath, fileName);
const blob = new Blob([new Uint8Array(byteArray)], { type: 'video/mp4' });
const url = URL.createObjectURL(blob);
this.videoPlayer.nativeElement.src = url;