An odd issue has been introduced with the Finale v25.3 update - for some Windows users, Finale will open deauthorized when launching the application by double-clicking on a Finale file (.mus or .musx), even after you have authorized the program. This issue can be preceded by a failure for Finale v25.3 to assert itself as the version of Finale that should open Finale files after installation.
This issue was resolved with the v25.4 maintenance update released on June 29th, 2017.
Comments
This problem only appears to occur when the Finale file you double-clicked to open the application is saved on a drive other than your computer's C:\ drive, so that could be anything not named C: (E:\ drive, D:\ drive, USB Flash Drive, etc.). If you don't want to use the workaround above (paragraph 3), you can try moving the Finale file to a location on your C:\ drive and opening it from there. Information added to paragraph 2 in main article.
This article has been updated with more information about the nature of this issue. In short, the problem occurs when a file is launched from a drive other than the drive upon which Finale was first authorized. Originally, this was believed to be any drive but the C:\ drive, but it is now apparent that this affects any drive (including the C:\ drive) upon which Finale was not initially authorized. The File > Open workaround still works to open files from other drives. Please see the article for more information and further clarification.
This issue was resolved with the v25.4 maintenance update released on June 29th, 2017. To get the latest version of Finale, please check out this article: https://makemusic.zendesk.com/hc/en-us/articles/230039927