Hello Pag1iaccio, if you haven't used Spine in several months, please try to download the latest installer and reinstall Spine.
You could also skip the update on the first run by going into the Spine folder created in your user directory, such as:
C:\Users\Erikari\Spine
and creating a file called:
version.txt
with just this text inside:
3.8.79
(it's the number of the latest version)