There are multiple reasons a download can be blocked (Safe Browsing and insecure connections are frequently confused). Since you say Chrome is "blocking it as dangerous", I think you're probably encountering a Safe Browsing warning. For Safe Browsing warnings, Chrome relies on Safe Browsing’s verdicts on the safety of downloads. To view our guidelines for flagging in Chrome, please see
https://support.google.com/webmasters/answer/3258249. That also has a link to show the Security Issues Report for your domain within webmaster tools, and additional support suggestions, including how to request a review from Safe Browsing.