Yeah, having the same Problem right now, stuck at the calculating part no matter how often i try.
First time using 7th Heaven, used to use bootleg so i am a bit at a loss here
edit:nevermind its just a few of them not downloading :/ so the problem might not be at my end, guess i will just wait ^^
edit2: in case this is the same for you, every mod with a date older than 2016 cannot be downloaded, but every older version has a newer version aswell further below e.g. a animation mod 1.0 released 9/2/2014 and the newer one version 2.1 released 11/11/2016