Issue: PDF Upload and Parse Failing

[Lycan-Xx]

Issue Summary

• Affected Feature: PDF file upload and text extraction
• Severity: Medium – core AI functionality remains operational
• Discovery Date: September 17 2025 (2 days post‑deployment)
• Estimated Fix: Immediately after hackathon judging

Timeline

• Sept 15: Initial deployment to Netlify
• Sept 17: Issue discovered during user testing
• Sept 18: Root cause identified and documented
• Post‑Judging: Fix impl

ementation scheduled

What Happened

After deploying StudyWise AI to production on Netlify (Sept 15 2025), PDF uploads began failing with a version‑compatibility error. The feature worked perfectly in local development.

Technical Details

Error Message

PDF processing error: The API version "5.4.54" does not match the Worker version "3.11.174"

Root Cause

A version mismatch between the two PDF.js components:

Component	Source	Version
PDF.js display layer (installed package)	npm ("pdfjs-dist": "^5.4.54")	5.4.54
PDF.js worker script (CDN)	https://cdnjs.cloudflare.com/ajax/libs/pdf.js/3.11.174/pdf.worker.min.js	3.11.174

Why This Happened

• Development used a local worker that matched the library version.
• Production pointed to a CDN fallback (3.11.174).
• The library was later upgraded to 5.4.54, but that version isn’t available on CDNJS (only newer builds like 5.4.149).
• The missing CDN version caused the API and worker versions to diverge, triggering the error.
• Mistake: I didn’t verify that the CDN actually provides the fallback version I was referencing.

Impact Assessment

• ✅ Still works: All features except PDF upload.
• ❌ Affected: PDF file uploads and text extraction.
• 🔄 Workaround:
  1. Convert PDFs to plain text with external tools.
  2. Copy‑paste text directly into the app.
  3. Use markdown (.md) files for formatted notes.

Why Not Fixed Immediately?

• Submission integrity: Hackathon rules forbid code changes during judging.
• OAuth complexity: Separate branches would break Google OAuth callbacks configured in Supabase.
• Risk management: Changes during judging could introduce new issues to already‑working features.

Technical Solution (Post‑Judging)

Quick Fix

// client/src/utils/documentProcessor.ts
const RELIABLE_CDN_VERSION = '5.4.149'; // use an available CDNJS version

Long‑Term Solution

Implement dynamic version matching (e.g., fetch the latest matching worker version at runtime) to prevent future mismatches.

Lessons Learned

1. Verify external dependencies: Ensure CDN versions referenced in code actually exist before deployment.
2. Production environment testing: Test all features in the real production environment, not just locally.
3. Dependency management: Bundle critical libraries locally instead of relying on external CDNs for core functionality.