Opera Developer 45 seems to work fine - except that having activated the sidebar to use Facebook Messenger (an excellent feature) there seems to be no way to get it to retract. With OD 44 I was able to click on the FBM icon to toggle showing/hiding it, but that does not seem to work on OD 45. It would be great to see that reinstated on the next update (I think the same comment holds for WhatsApp too).