I have a game I am making, but I have run into a brick wall. My player is not receiving any messages. It uses Dynamic physics type and it is set to receive any message. I want it to receive a message from a child circle below it. They are both in the same scene. I want the circle to tell the player that it is on the ground so the player can know when to jump.
Possible cause: combination with keyboard sensor
Just as it is the configuration looks fine. But there is a danger.
You combine the message detection with keyboard detection. That means the actuator will only be activated when you hold the specified key and receive a message at the same time.
It might be you want to activate the motion actuator when either the key is pressed or a message is received. In that case I suggest to replace the AND controller with an OR controller.
To analyze if the message can be received at all, you can disconnect the keyboard sensor (leaving the message sensor).
To analyze if the motion actuator has any effect on your object, you can disconnect the message sensor (leaving the keyboard sensor).
I hope it helps
Possible cause: no collision
This would result in never activating the message actuator = no message at all.
You can analyze this situation by connecting a different actuator that does something you can notice while running the game (e.g. turning the object via motion actuator, or counting a property that is shown in the debug overlay).
If that actuator does not show something your collision detection has a problem -> different question.
Otherwise this answer does not help you.