Attach (recommended) or Link to PDF file here:
[1.pdf.lin (1).pdf](https://github.com/mozilla/pdf.js/files/5780764/1.pdf.lin.1.pdf)

Configuration:
- Web browser and its version: FireFox 84.0 
- Operating system and its version: macOS 10.15.7
- PDF.js version: 2.7.262
- Is a browser extension: No

Steps to reproduce the problem:
1. Open the PDF with pdf.js.
2. Found the text of this PDF disappeared.

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/18492951/103877578-3d9da400-5110-11eb-8d84-4edd9aa1298b.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/18492951/103877735-6d4cac00-5110-11eb-9e76-7f3d9330086b.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

dfference[ndex] = data.name;
            } ele {
              thrw new FrmatErrr(
                `Invald entry n 'Dfference' array: ${data}`
              );
            }
          }
        }
      } ele f (Name(encdng)) {
        baeEncdngName = encdng.name;
      } ele {
        thrw new FrmatErrr("Encdng  nt a Name nr a Dct");
      }
      
      
      f (
        baeEncdngName !== "MacRmanEncdng" &&
        baeEncdngName !== "MacExpertEncdng" &&
        baeEncdngName !== "WnAnEncdng"
      ) {
        baeEncdngName = null;
      }
    }
    f (baeEncdngName) {
      prperte.defaultEncdng = getEncdng(baeEncdngName).lce();
    } ele {
      var SymblcFnt = !!(prperte.flag & FntFlag.Symblc);
      var NnymblcFnt = !!(prperte.flag & FntFlag.Nnymblc);