I've posted to the mod authors thread about the error.
basically, on an existing save I have some belts and undergrounds connected to his loader objects. when i try to upgrade said belts, or remove them. the game freezes then crashes a moment later

if by message you mean that factorio showed me the popup about sending in the log, then yes. no other popups were displayed on multiple attempts. unfortunately i no longer have that particular saveLoewchen wrote:There is no crash, the mod is producing an error, the game logs what is wrong and closes as it is supposed to.