One possible scenario is that you have a newer and an older version of Final Draft installed and the other version is open. Only one version of Final Draft can be open at one time, so check to see if another version is running. If there is, close it and you should then be able to open the version you want.
If Final Draft still doesn't open, please open a support ticket and a technician will investigate.
12013
https://fd.support/3WYAZYi