All my downloadable contributions (skins, genre lists, Picard scripts, translation files, etc.) use abbreviated Bit.ly links.
As we speak, Bit.ly is falsely blocking a lot of these links, warning that they might not be 'safe'.
Obviously this is incorrect. All these download links only contain either (compiled) xml or txt files.
Bitly provides no opportunity for me to contact them directly, so my complaint about this was done using the form that they link to on the page that informs that the specific download link is blocked.
It's been a couple of days now and I haven't gotten a response from them yet.
If you are prevented from downloading an addon/contribution of mine due to this, it may help if you report the false security blocking to them.
(Contrary to what that page suggests, you don't need to enter your g00gle account. Only an email address, which doesn't need to be a functional one, unless you are interested in possible feedback from them.)It might be good to also add the link to this specific post/thread in the 'Comments' field:
https://getmusicbee.com/forum/index.php?topic=36456.0Thanks to those helping in trying to solve this problem.