Steps to reproduce:

1. download instalation deb package from download web page and install it.
2. run apt update

Result:
error message saying "repo...contains no Release file..."
Expected:
Release file can be downloaded and subsequent installation works.

If i view the repo directora in a browser and click on the release file, i get an "application/octet-strem" in response, this is likely the cause for the failure. Trying to access a Release file from ftp.debian.org repo, this is opened in the browser, so it is not octet-stream. I guess this is a server or encoding issue, please check.