Attaching Scripts to objects

[Parsiuk]

Just bought LW today. I'm going through tutorials and I'm trying to assign a script to an object (the fan tutorial). I click on an object and then I select my rotation script. Now if I try to run/debug the game, nothing happens. If I select a different object after assigning a script, and then select my fan again, then the script disappears. It's no longer assigned.

https://www.leadwerks.com/learn?page=Tutorials_Lua-Scripting_Introduction-to-Lua

I'm on Debian 10.

Any ideas what I may be doing wrong?