Jumpthru Platforms Sometimes Not Passable

Hi, I have a serious problem with ladders. I’ve tried dozens of alternatives but haven’t been able to solve it.

I want my character to go up and down the ladders with a touch button. It works perfectly: but once in a while, when reaching the top, if I move right or left and press the button, the character gets stuck.

The conditions are met (the red messages show that the condition is verified) but the character doesn’t go down.

Then suddenly, if I move away, sometimes it starts working again.

I’ll leave you a screenshot and the project. Thank you!!!

I’ve conducted more tests. I created an invisible ladder around the player to see if it was a collision problem with the platform, but even in that case, the character doesn’t go down.

I’ve modified the collision mask into various shapes and something even stranger happens.

With a mask only on the face, the character starts descending the ladder but then gets stuck when the collision mask intersects the jumpthru platform.

And this only happens sometimes! Is it possible that not using Gdevelop’s default controls causes a conflict between ladders and platforms?

Shouldn’t ladders have ever priority over platforms?


I have found the origin of the bug. Sometimes a jumpthru platform can be passed through by pressing the down button, and sometimes it can’t.

I turned off all events. This happens randomly: sometimes it always works, sometimes it never works.

I am using the latest version of Gdevelop on Windows 10.

Is there a way to identify the origin of the bug, perhaps using debugging?

I will change the title of the post to be more accurate.

Hello, Ondaluce!

In my game I faced a particular problem with jumpthrow, but I don’t use stairs. It didn’t work if my character was moving fast. So I added it to the actions to change the character’s speed and it started to always work, but with the effect of the character slowing down/stopping when jumpthrow.

Your problem seems different, but I thought it would be worth sharing this close experience.

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Thank you so much, I will also try that. However, I discovered that sometimes the game blocks the ability to descend from platforms by pressing down, while other times everything works normally. To be sure, I uninstalled Gdevelop, deleted temporary files, and cleaned the registry. Tonight, I will reinstall everything, hoping to resolve the issue that way.


When the character descends from the ladder, I increase their y position by a few points, forcing the platform to make him fall. At that point, the character continues on the ladder.

I hope, however, that this bug is not a sign of a more serious problem in the project files or in Gdevelop.

You may try whitout jumptru…
I would do like this.
Use standard platform behaviour;
when you need to go down disable the behaviour and when your player is not in collision anymore re-enable the bahaviour again

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Thank you for the advice. It was an option, but I would have had problems with other events.

Now I’ve resolved it with a patch, but I would like to understand why a normal event like descending from a platform might stop working.

Could it be that the project is corrupted? Or that some file is damaged? Or is it a bug in the program? I hope someone who has encountered this can find a solution.