1. **Simplified nginx configuration:**
- Changed from `root /data` back to `alias /data/uploads/` which is the correct way to map `/uploads/` to `/data/uploads/`
- Removed potentially conflicting location blocks
- Fixed the error handling to not redirect upload 404s to the index page
2. **Improved startup script:**
- Added checking and reporting of directory permissions
- Added explicit chmod during startup
3. **Simplified Flask route:**
- Removed all the complex debugging code
- Returned to a simple `send_from_directory` call
4. **Added a basic test file:**
- Created ping.html to test basic nginx functionality
