When uploading a pdf file, I get Warning: Unimplemented widget field type "null", falling back to base field type at pdf.worker.js. The file is not loading.
I'm using the chrome browser. All other files are processed fine, but this one is not. Help solve the problem.
[usn2020.pdf](https://github.com/mozilla/pdf.js/files/5936611/usn2020.pdf)

if (
      typeof PDFJSDev === "undefined" ||
      PDFJSDev.test("!PRODUCTION || TESTING")
    ) {
      assert(
        this.data.defaultAppearanceData,
        "Expected `_defaultAppearanceData` to have been set."
      );
    }
    const {
      localResources,
      appearanceResources,
      acroFormResources,
    } = this._fieldResources;
    const fontNameStr =
      this.data.defaultAppearanceData &&
      this.data.defaultAppearanceData.fontName.name;
    if (!fontNameStr) {
      return localResources || Dict.empty;
    }
    for (const resources of [localResources, appearanceResources]) {
      if (resources instanceof Dict) {
        const localFont = resources.get("Font");
        if (localFont instanceof Dict && localFont.has(fontNameStr)) {
          return resources;
        }