Allow Read/Write access to ALL meshes used for Mesh Colliders

Check the following page in the Unity documentation for more details about the trade-offs.

https://docs.unity3d.com/ScriptReference/Mesh-isReadable.html

To fix this error:

1. Select the mesh in your project and go to the ‘model’ tab of the import inspector

2. Check the ‘read/write’ checkbox

3. Click ‘Apply’