Quote: "Worse than that, sometimes boolean just... stops working. I once tried to make a high poly dice, using geospheres to get the dimples. I managed about 8 dimples before boolean just stopped working and made holes instead of dimples."
Because boolean requires that the mesh your operating on doesnt have any holes, to check for holes select the source object and use the stl check modifier and it will point out any gaps in the tri`s.
Also, you shouldent have used boolean to get the hole in the top as you can see you really messed that bit up, and you should use a better matriel than just plain black.
Hallowed are the ori.