Uploading of XLS Form

1. What is the issue? Please be detailed.
I am trying to upload an XLS Form and I am getting and error 499. I have no ideas what is the problem here

2. What steps can we take to reproduce this issue?

3. What have you tried to fix the issue?

4. Upload any forms or screenshots you can share publicly below.

5 posts were merged into an existing topic: Failure to upload XLS Form