So, in the Anim editor, you can right-click-and-drag to navigate. If you do this anywhere in the notifies window (suppose you are placing notifies while zoomed in for accuracy and need to pan to the left to place another one, without wanting to zoom out), because the notifies window cannot be panned VERTICALLY, UE4 will only register your panning if you never, ever, ever move the mouse vertically.
Try it. Scroll down to the notifies window in a Montage, zoom in, and right-click-and-drag left and right. Odds are you will be able to pan just a little bit before your hand starts to slip down and the engine goes “oh wait, you must have meant to do a vertical pan!”, immediately cancels your horizontal movement, and instead starts scrolling vertically. Once it switches from horizontal-scrolling-within-notify-timelines to vertical-scrolling-of-anim-options, the ONLY WAY to get it to switch back is to release RMB and do it again.
This is really, really, really, really headache-inducing. It makes trying to do extended work on notifies almost impossible because the engine is so crappy at registering horizontal pans.
IMO the correct way to have this functionality set up would be the way it’s set up if you peform the same gesture in the curve editor; right-click-and-drag pans vertically, limited to the region in question (so you could use it to scroll vertically in a long list of Notify tracks, but never beyond that list) and DOES NOT INTERRUPT HORIZONTAL PANNING (so if you pan up while panning right, it pans up-and-to-the-right, rather than immediately eliminating all horizontal movement and locking to the vertical axis).
Thanks for bringing this to our attention and apologies for the trouble its causing you, it sounds incredibly frustrating! This is a bug and not how the notify panel used to work. We will look into it.
Can I ask what version of the editor you are using?
I honestly can’t remember if it was always like this or not… I only just noticed it because I started bulk-copying all of my notifies from Montage assets to their child anims and trying to place dozens of notifies in succession it really starts to wear on your patience
I’ve managed to reproduce this behaviour. The issue seems to be that if the animation panel can scroll, then on moving the mouse vertically the entire panel grabs control of the mouse and takes the input away from the notifies track, hence horizontal movement stops working.
I’m going to look at fixing this ASAP, in the meantime however a workaround for you is to make sure that the panel doesn’t want to scroll, which will stop this behaviour triggering. You can do this by collapsing sections or by resizing the layout so the panel is bigger.
I’ve included some screenshots to show what I mean about the panel wanting to scroll in case the above isn’t clear
If you build your own editor from the source on github you should be able to just grab that change (or recreate it yourself). If not then you should get it in the next release (at least 4.8 but I’ll see about getting it included in any further 4.7 releases if we make them).