Can't copy from Pages to Keynote on Mac - SOLVED

This has happened to me a few different times, and the solution always seems to be making sure that both Pages and Keynote are both updated to the most recent version of each application. I had just recently updated Pages, and didn't realize that there was an update for Keynote as well. After updating Keynote, copying and pasting in between both apps worked seamlessly.

-- The reason I posted this as a question as all the other threads with similar questions were closed, and not one of them explained it this straight forward, or if at all.