Converting old world's deletes half the worlf and crashes game after 20 to 30 seconds

Converted my old world over to the new mine craft , not only did it delete half of my builds near the world borders without any options of turning off infinite world or options to not delete world borders , but then after only 20 seconds of walking around, game crashes to black screen and forces me to do a hard reset on the console to get anything to work. Severely broken and will continue with my xbox one version until game breaking bugs such as this are fixed.