Unable to update Keynote

In addition to Camelot's questions, how much free space to you have on your internal drive? At System Settings>General> Storage, my Mac says 745 GB of 1TBB used. What does yours say?

Try these things:

• Restart the computer
• Re-start in Safe Mode. This bypasses certain potentially disruptive processes, and it often helps. Safe Mode is different for different computers, so see this: 

           Start up your Mac in safe mode - Apple Support 

Update from which version?

to which version?

How are you doing it? (or trying to)?

What happens when you try? What's the error message (if any)?