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 (!isDict(dict)) {
      return null;
    }
    const bbox = [
      0,
      0,
      this.data.rect[2] - this.data.rect[0],
      this.data.rect[3] - this.data.rect[1],
    ];
    const xfa = {
      path: stringToPDFString(dict.get("T") || ""),
      value,
    };
    const newRef = xref.getNewRef();
    const AP = new Dict(xref);
    AP.set("N", newRef);
    const encrypt = xref.encrypt;
    let originalTransform = null;
    let newTransform = null;
    if (encrypt) {
      originalTransform = encrypt.createCipherTransform(
        this.ref.num,
        this.ref.gen
      );
      newTransform = encrypt.createCipherTransform(newRef.num, newRef.gen);
      appearance = newTransform.encryptString(appearance);
    }
    dict.set("V", isAscii(value) ? value : stringToUTF16BEString(value));
    dict.set("AP", AP);
    dict.set("M", `D:${getModificationDate()}`);