STR:
  - Go to https://mozilla.github.io/pdf.js/web/viewer.html
  - Click on "Open File" and open a pdf

The `Download` button and the `Current view` one just disappear.
I can reproduce this bug with Firefox nightly, Chrome stable and Epiphany on debian.
Promise.all(moreInfoText).then(parts => {
        console.error(message + "\n" + parts.join("\n"));
      });
      this.fallback();
    }
  },
  progress(level) {
    if (this.downloadComplete) {
      
      
      return;
    }
    const percent = Math.round(level * 100);
    
    
    
    
    if (percent > this.loadingBar.percent || isNaN(percent)) {
      this.loadingBar.percent = percent;
      
      
      
      
      
      const disableAutoFetch = this.pdfDocument
        ? this.pdfDocument.loadingParams.disableAutoFetch
        : AppOptions.get("disableAutoFetch");
      if (disableAutoFetch && percent) {
        if (this.disableAutoFetchLoadingBarTimeout) {
          clearTimeout(this.disableAutoFetchLoadingBarTimeout);