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)

constructor(begin, end) {
    super(`Missing data [${begin}, ${end})`);
    this.begin = begin;
    this.end = end;
  }
}
class XRefEntryException extends BaseException {}
class XRefParseException extends BaseException {}
/**
 * Get the value of an inheritable property.
 *
 * If the PDF specification explicitly lists a property in a dictionary as
 * inheritable, then the value of the property may be present in the dictionary
 * itself or in one or more parents of the dictionary.
 *
 * If the key is not found in the tree, `undefined` is returned. Otherwise,
 * the value for the key is returned or, if `stopWhenFound` is `false`, a list
 * of values is returned. To avoid infinite loops, the traversal is stopped when
 * the loop limit is reached.
 *
 * @param {Dict} dict - Dictionary from where to start the traversal.
 * @param {string} key - The key of the property to find the value for.
 * @param {boolean} getArray - Whether or not the value should be fetched as an
 *   array. The default value is `false`.
 * @param {boolean} stopWhenFound - Whether or not to stop the traversal when
 *   the key is found. If set to `false`, we always walk up the entire parent
 *   chain, for example to be able to find `\Resources` placed on multiple
 *   levels of the tree. The default value is `true`.
 */
function getInheritableProperty({