I have a Kingdom project from another author. When i try to create an horizon, it allows me to enter the horizon management and name the horizon to create. But when i click apply, nothing happens (horizon it’s not displayed on project tree, so i cannot select it)

Also, I cannot import new horizons to the project, but i can edit the one that was already created.

Could it be that i have 8.7 32 bit version and the project was from an 8.8 version?
Thanks!