The problem is nothing that you are explicitly doing. I think that what is happening is that an instance that has already been destroyed is being queued to be destroyed again, the runtime normally handles that, but from what I am seeing there could be a problem with that logic that would eventually lead to a crash.
I am just guessing though, even if that was the problem, there are a few different places that attempt to destroy instances, so it's not easy to pin down the problem without looking at a project.