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.
if (!this.pdfViewer.pageViewsReady) {
      this.l10n.get("printing_not_ready").then(msg => {
        
        window.alert(msg);
      });
      return;
    }
    const pagesOverview = this.pdfViewer.getPagesOverview();
    const printContainer = this.appConfig.printContainer;
    const printResolution = AppOptions.get("printResolution");
    const optionalContentConfigPromise =
      this.pdfViewer.optionalContentConfigPromise;
    const printService = PDFPrintServiceFactory.instance.createPrintService(
      this.pdfDocument,
      pagesOverview,
      printContainer,
      printResolution,
      optionalContentConfigPromise,
      this.l10n
    );
    this.printService = printService;
    this.forceRendering();
    printService.layout();
    this.externalServices.reportTelemetry({
      type: "print",
    });
  },
  afterPrint() {