I happend to run into this by mistake. If collectionfactory.load() is called twice on a dynamic collection factory without unload() being called in between, the app crashes at the following assert:
Assertion failed: (preloader->m_Request[0].m_FirstChild == -1), function UpdatePreloader, file …/src/resource_preloader.cpp, line 731.
Crashdump is available if you need more info and this was on MacOS running the Defold 1 editor.