Guild of Writers

I added a white face over the right side of the picture to show you where is the problem ("BarrierCollider" object); there's a collision here but it shouldn't...

I’m not a Blender user but the principle should be the same. Have you applied a “hull” collision which will encompass the whole object? What you need is an “exact” collision which will bound the exact shape rather than the area it inhabits.

Thanks for your message Semjay.
This object is the collider (left side of the picture), I applied a Triangle Mesh collision, but in the game it seems to be a Convex Hull collision (right side of the picture).

Edit:
The white face is where the floor is, with a floor collider; there are holes in the floor and in its collider, but in the game I don't fall through the holes.
If I export the Age without this object, it's OK, I fall through the holes; but if I export with this object, it isn't OK, I don't fall through the holes.

I found the solution : I added 24 faces (so, 32 in total) to the collider.

Triangle mesh will create a box around some objects. Did you also make it a wire mesh & add the collision property...
string type collider

Thanks for your message melvin.
Yes I did (Korman 0.13).
But like I said, it's solved.