Problem with collider

I am developing a game which involves a flying drone delivering parcels. I have built the drone and made a script to fly it but when I put in obstacles it will not collide with them and instead it goes through. I have colliders on all of the actual objects and is trigger is unchecked but it still will not collide and goes straight through could you please tell me why this is happening.

Thanks in advance.

The best guess is that your drone has no Rigidbody attached, or your script is acting ‘kinematically’(i.e moving drone by modifying its transform, not by adding force).

you may check your collider … may be it is wrongly made…
you may use another collider object,they are available in standard assets