Please Help, I am getting 404 error

I think you were trying to download a protected file from the email you received. I suggest you contact the form owner about this so they are made aware of this. If you own the account, you can unrequire this option in your privacy settings to allow immediate download of all the uploaded files.

Guide: How to Unrequire Login to View Uploaded Files

If this remains checked, only the form owner can download the files if they are logged in to their JotForm account. Unchecking this option will allow users to download the files immediately without logging in to JotForm.