Updated to iOS 9.1 and "latest" version of iTunes, but iPhone isn't recognised

I have just updated both my iTunes and iPhone. The iPhone is running 9.1 and iTunes 11.4. When I try to sync my phone, I get a message telling me it wont sync because it's not the latest version of iTunes. However, when i go into the iTunes software update, it tells me I'm running the latest version. This is beyond frustrating, so I hope someone can help.

I'm using a MacBook, with 10.6.8

Thanks in anticipation of an answer!