ChatGPT Says “Unknown Error Occurred” for PDF File Uploads

Many users have recently run into a frustrating issue: when uploading PDF files to ChatGPT, the tool fails halfway through and throws an error message saying “Unknown Error Occurred.” This has impacted productivity for people who rely heavily on PDF uploads for summaries, Q&A, or document analysis.

ChatGPT Says “Unknown Error Occurred” is reported on Windows, macOS, Chrome, safari and iPhone, Android apps as well.

ChatGPT Says “Unknown Error Occurred” 2025

📂 What’s the Problem?

Users have reported:

PDF files begin uploading but stop midway with an “Unknown Error Occurred” message.
Other file types like .DOCX, .PNG, and .TXT upload without issues.
Problem persists across different devices, browsers, and even after creating new accounts.
PDFs that were working earlier now fail to upload.

🔍 Possible Causes (Based on Community Feedback)

Image-based PDFs (e.g., made from screenshots) with no embedded text.
PDFs missing OCR (Optical Character Recognition) layer, making them unreadable by ChatGPT.
Corrupt encoding or export settings during PDF creation.
Temporary restrictions or bugs on the ChatGPT platform side.

✅ Fixes That Actually Work

1. 🧾 Use OCR Tools

Convert the PDF using an OCR converter before uploading.

Tools like iLovePDF OCR, Adobe Scan, or Online OCR can help.
After conversion, ChatGPT usually processes it smoothly.

2. 💾 Embed Text During Export

When creating a PDF (especially on Mac or using print-to-PDF options), select “Embed Text” or “Save as Searchable PDF.”

3. 📦 ZIP Your PDF

If upload fails, try zipping the PDF and uploading the .zip file to ChatGPT.

This trick has bypassed the error for some users.

4. 🔁 Use Another ChatGPT Account

Oddly, some users found that switching accounts temporarily solves the issue.

Possibly related to server-side restrictions or a session cache problem.

🧹 Bonus Tips

Clear browser cache and cookies
Try incognito mode or a different browser
Wait and try again after some time — it may be a server overload issue

💬 Final Thoughts

The “Unknown Error Occurred” problem in ChatGPT’s PDF upload system is annoying — especially when all other file types work. But with a few simple workarounds, like OCR conversion or using a zipped file, the error can often be bypassed.

Let’s hope OpenAI releases a fix for this soon. Until then, these user-tested tricks might save your workflow.