I found an error of parallel stabilization process: if try to stabilize two fragments on timeline with just same numbers of frames (as example 900). Then you begin second processing it uses thirst thread which is already running and start from already proccesed in thirst thread place (for example from 300 frame or any). If you cancel, it willl affect thirst thread too. Calculation mixes and both will do wrond stabilization with bad result. If you cut just one frame so it will be 899 frames of second fragment, stabilizer will start another separate thread of processing, and everything will be fine.
This error is in beta 14.9 and earlier versions and releases. (windows 10 all last updates)