Yes, I confirm, I've downloaded the 1.51 version, I've the "cloud" icon on the left in the editor, I can see the menu and change values, but it says on the top right "Script not defined with No control 123.735" (123.735 is the speed I've chosen).
And if I try to launch the mission, after clicking on play, it says " No entry 'config/cfgWorlds.51_demo.' "
I hope someone had a solution or maybe Gammadust will come back...