Rigidbody falls through plane

Yes this question has been seen a lot. But the posts related to this doesn’t help.

I’m using a Rigidbody on an imported Blender “project” (I don’t know the lingo here). It’s in a weird shape:

The tank is made of several components that are joined together in a single Tank empty gameobject, thus the RigidBody and Mesh Collider are used for the GameObject rather than every individual piece of the tank. Even if I apply a RigidBody and Mesh Collider to the body exclusively, the problem prevails. This is its properties:
111968-capture.png

So clearly, the tank is falling through the fall, which has a mesh collider with Convex ticked in and is a plane mesh. Since Is Trigger is off and Convex is on for both colliders, why does the tank fall through? Other Rigidbodies present with Gravity on do not fall through (one of them is a cube with a Mesh Collider with Convex ticked in, Is Trigger off).

try setting Collision detection to continuous. tell me if that works

There is No Mesh assigned to the Mesh Collider, the problem is there… Try adding Mesh Collider Component to the Object which have mesh i.e to the chil game objects. If the objects have no mesh then I suggest you to add Box Collider. Your Object will not fall down and make it confirm that there is Collider attached with Plane too.
It will solve your problem!