Hi, I’m adding more detailed information because I’m experiencing the exact same issue, and it doesn’t seem to be an isolated case or related to a specific file.

App version: ChatBox for iOS, version 1.18.1

Device: iPhone (latest iOS version)

Platform: iOS (the Windows desktop version works perfectly with the same files)

Error symptoms:

• I cannot upload any PDF files or Excel files (XLS/XLSX).

• When I try to attach them, a red exclamation mark icon appears in the lower-left corner, and the file never uploads.

• The issue happens with both large files and very small ones (e.g., PDFs of just a few kilobytes).

• I tested files from different locations (iCloud Drive, “On My iPhone”, files saved from WhatsApp, etc.), and the result is always the same.

• However, uploading images (JPG/PNG) and text files (TXT) works without any problem.

Additional tests:

• The same PDFs and Excel files upload correctly when using ChatBox for Windows, with the same model configuration.

• I’ve tried renaming files, converting them, simplifying them, and changing their storage location. The behavior doesn’t change.

• This strongly suggests the issue is limited to the iOS app’s document upload or preprocessing module for PDF/Excel, while the handlers for images and text files work correctly.

If you need sample files, logs, or any additional details to reproduce the issue, I’m happy to provide them.

Thanks for looking into this — hope this helps identify and fix the problem soon!