error Please correct the errors in the form and try again. create "" failed (fetches failed) latest_version - failed converting

[prince20112003]

I am trying to add some software, so I get an update notification whenever there is a new update available. However, I have encountered some issues. currently I am trying to add greenbone. The link to all the release is https://www.greenbone.net/en/roadmap-lifecycle/ and the RegEx I am using is \d+.\d+ .
the error i am getting is :
create "" failed (fetches failed)
latest_version - failed converting.

error-greenbone.txt