RobotStudio event

the function play Simulation does sometime not work in Robotstudio 2023.4 and 2024 also

I do some simulations with Robotststudio using Buttons, Mover.... with my pupils.
Some of them use Robotstudio2023.2 everything works.
Some of them use 2023.4 - and 2024 here the problem starts when we start the simulation nothing happens most of the time 
Sometimes it works normaly - i cant find why??