Is there a way to disable the autosave in UE4?

No way. Editor is saving current state of the engine. If you’ll change something during saving process - this may break state of assets which were already saved. However, having “Cancel” for auto-save would be really nice. Auto-save timer doesn’t work correctly in many situations, for example - when I’m importing a complex scene, what takes a very long time, auto-save may be triggered immediately after import.