This is a simple question, and everything in my script appears to work properly. The mesh goes collide able when enabled but I can still go through it. What is wrong?
If it's a problem with the script, try to place the mesh you made in the workspace and set the collision manually without any script changing it. If you can collide with it then, it's a problem with your script.
Alternatively, if you've created a custom mesh with MeshPart, then it's possible that the default collisionfidelity could be messed up, which can be even more likely if the mesh that you created was orignally a smal sizel. If you need to make a small mesh, make the original mesh larger first, and then try to downsize it to the size that you want.