Why is my Merlin 2 license key not valid anymore after re-installing the software?
Merlin 2 licenses are not valid for Merlin Project. Please therefore make sure, that you have downloaded and installed the correct version, i. e. Merlin 2.
Merlin 2 is available for download here. Please note that Merlin 2 is no more supported since macOS 10.12 (Sierra).
If you have macOS 10.12 or newer, you will need to upgrade to Merlin Project. This version is available on subscription.