Failed to Fetch error while uploading a PDF

While uploading a PDF, I’m getting failed to fetch error. Attached the screenshot

Pickaxe link - https://beta.pickaxeproject.com/axe?id=Andrew_Chen_TYUJ9

Any idea how to fix this?

If you consistently get that error everytime it means something about that specific PDF doesn’t play nice with our system. And I would try to convert it to other file types and upload it.