https://github.com/nextcloud/files_pdfviewer/issues/381#issuecomment-845806364
Problem with spaces and other % chars in file path or name.
Use this file https://raw.githubusercontent.com/nextcloud/files_pdfviewer/6d81ffbb65c3758bece144e0aff07b4a0ad20eef/js/files_pdfviewer-main.js for apps/files_pdfviewer/js/files_pdfviewer-main.js