no collision is working

none of the engine collisions run here, objects go through even with a collision. help me!

You have to put actions on colision. The condition “object and A and B are in collision” is just a trigger. Depending on the game you are doing, but for platform game for examples, you have to give a behaviour to object on ground for example and being able to walk on it. Take a look on example provided with the software, and follow tutorials on the wiki to learn the basis.

Also, if it’s a bug… well ? what are you using ? GDevelop ? GDevApp ? wich OS is used ?

I’m using gdevelop 4, windows 7 operating system, give me an example of collision because when I do look like the ones in the examples the objects do not collide they just traverse.

It’s normal that they traverse, the collision have to get an action attached to, for example :
object A is in collision with Object B, then destroy object B.
or : Object “Player” is in collision with object B, then make -1 to health point of the player

I get it, but if it’s just to have a simple collision of one object and another?

Use the action to separate two objects:

Player is in collision with Wall >> Separate Player from Wall (only Player will move)

A collision, as GDevelop understands it, is two objects overlapping on the screen. It doesn’t mean two objects hitting each other and bouncing apart. You would have to tell it that’s what you want to happen (as with Lizard-13’s example above).

The exception to that is if you use the Physics behaviour. Then, the objects will automatically bounce off each other (as if they were solid) without you having to create an event to tell them to.