Can't Display and Downloaded as Blank PDF File

Please tell us what happens, what you expected to happen, and why you think it is a bug in the software.

Pdf Viewer not display pdf file, and blank if i downloaded the file.

PDF.js v2.6.347 (build: 3be9c65f)
Messege: Invalid PDF structure.

But if deprecation_warnings is set to ON pdf viewer displayed correctly

  1. Which version of OJS are you using?
  2. Have you made any changes or updates recently?
  3. Is your “files” folder where it is shown in the config?