Cannot upload open web apps modules

Hi everyone, Whenever I try to upload an open web app module via the manage apps page in the reference application, I get an error App is not a zip archive. I am currently on version 2.6.0 of the reference application. Please how do I solve this issue thanks.

The .Zip file can be found here

Can you attach the zip here such that we also try it out?

I have added a link to the .zip file

Are you able to upload it at