Obviously, the cube needs to be inside of a disabled trigger_catapult, which is then enabled. However, when the trigger is enabled, the cube won't move. -> trigger_catapult doesn't check for collisions when its enabled.

Another thought was to put the trigger slightly above the cube, which is afterwards pushed into it by the robot arm. This, though, makes the cube uncontrolable. It will miss the target and hit other objects in the room.

Eventually, I made a 1 unit thick physics clip above a 1 unit thick catapult that got deactivated when the cube was supposed to be launched. I never found another way to do it.

Brainstone, have you checked the flag "physics objects" and set the "Physics Objects Speed" to a value enough to catapult the cube?

In this thread 2 ppl suggests a good workaround: use a trigger_push below with direction of push set up (-90 0 0) with some low push value (that makes your cube reach the trigger_catapult ofc ), and problem solved.

Also, chariots chariots. What was the pre-DLC2 rank for having over 500 posts?