You bought this app, so you get to choose which build you run. If an update ever gives you trouble, install the one before it and keep working. Your license key works on every build listed here.
Installing an older build does not stop automatic updates. markdossier will offer the newest version again unless you turn updates off. Versions older than the ones listed here are not offered at all: they shipped with an updater that can no longer reach us, so anyone who installs one cannot update forward again without downloading by hand. We would rather not hand you a version that creates a new problem while you are solving another one.
On a Mac, this is the direct build that accepts a license key. If you bought markdossier on the Mac App Store, update through the App Store instead - App Store builds use Apple's own purchase system and do not accept license keys.