Mac – Cannot update to Safari 11

So, is there a general way to ensure my Keynote presentation time is uninterrupted?

Unless I know I'll absolutely need network access, I just turn off all network interfaces while I'm giving presentations. This effectively blocks any auto-update routines from running without having to disable and then re-enable the feature in any piece of software I might want to use during my talk.

I'll also shut down all the programs I don't absolutely need running during a presentation. In particular email, instant message and any sort of communication apps that could cause a notification bell or a preview to pop up on my screen get shut down.

I'll pause Growl (Growl icon in menu bar -> Pause Growl) so notifications don't interrupt my presentation.

And I'll switch from any customized backgrounds I might have to some corporate logo backgrounds.

I'll even clear my browser history. Not that there'd be anything lewd, but there might be competitor's websites or company-sensitive information that can be given away by URLs that auto-complete when I start to type in the browser.

That's my usual pre-flight check before I use my laptop in public presentation.

Seems to me you should contact apple support.

I can think of several diagnostics here.

1. Is it apple ID specific?
2. Is your DNS servers having trouble or not local enough so apple knows where you are and which CDN node to use? Make sure you use the ones from your ISP.
3. Lastly, you may want to test with another user account, and make sure the app store functions correctly there.
4. If you can get away with it, does it work in Safe Mode? (holding down shift at boot)
5. When you run a traceroute, is the latency really high? What about speed?
6. What OS are you using? Snow Leopard, Lion or Mountain Lion. Mountain Lion probably has a much more integrated app store, and it might work better for you. (major surgery though.)