I created a menu popup when a player presses the designated key. I’m able to enable/disable the player’s mouse but can’t seem to figure out how to stop the screen from rotating as the player moves their mouse to and around the menu. Any suggestions?
Thanks!
Try to set the cinematic mode from the player controller to true.
There are a couple of recently added nodes for when using UMG, drag the blue wire off of Get Player Controller and check the Input section, here are a couple of useful functions:
Hope that helps! 
Yup… “Set Ignore Look Input” and “Set Ignore Move Input” is what you would use before the UMG stuff but I suppose now with the “Set Input Mode UIOnly” it’s a bit easier.
Great, that worked! Thank you all for the suggestions! Here is the right half after the modification for others to reference. I will say though that after the menu closes I still have to click in the screen for the game to accept mouse movement again. Is there a way around ? I fiddled with the other functions in 's post but haven’t had any luck so far.
Try “Set Focus to Game Viewport”
In C++ from the Player Controller use:
// Stop Camera Rotation from the player input
SetIgnoreLookInput(true);
// Enable Camera Rotation
SetIgnoreLookInput(false);