...a new .capx when you have done everything right in your project but still it crashes on export?
So once again, no mistakes in code, no 3rd party stuff, only, let's say, one defective power of two sprite which must not be defective at all(at least I think so). And this is only in your project. So when you start a new project to reproduce a bug, this bug doesn't appear at all.
How can I report a bug when it's not reproducable but it's clear that it's a potential bug in the program?