Hey all,
There are some known issues with context menu in 4.5, and they have been fixed with a new menuing system which should make it into 4.6. Until then, you can go to Editor Preferences > Experimental and enable Use New Blueprint Menuing System. This will fix many, but not all, of issues currently present with context menu in blueprints. As a side note, you may need to switch this off and then on, as casting options don’t always show up with it on, but should when it’s off.
Thanks for your patience as developers build a better menu system!