Bug: PDF Attachments of Certain Names Cannot Be Loaded or Saved.

Factors: The Bug does not exist in other reader programs. Attachment files of all names are accessible in both Foxit Reader and Mozilla Firefox. That is to say, the error pdf attached works as intended in those programs. Because of this, we doubt this is a symptom of our PDF creation tools. We deduce it is only an issue of Adobe's Acrobat Products.

Process: The PDFs in question (Attached Error and Working) were created using pdf-lib in JavaScript. The file data was downloaded in a JavaScript Environment and Packaged via pdf-lib's "attach" method. In the attached working pdf, the files were attached with a generic name based on the order received (format: myFile[i].pdf). In the attached error pdf, the name was gathered from a received JSON object, then mapped as a parameter of the "attach" method. Both contain the same file data, with different file names. In both cases, the data integrity was verified by loading the data as the blob came in, prior to attachment. Finally, we passed in the string directly via a string literal, rather than the derived JSON name, with the same results. When accessing from Acrobat, the working pdf opens all attached files as intended. When the error pdf is accessed in Acrobat, attempting to open some (but not all) files will not result in the file opening. Attempting to save those files to another folder will result in an error (image attached).

Version(s) Verified: Acrobat Reader 2022.003.20322, Acrobat Pro DC (Classic) 2015.006.30527