Did you ever get this notification when plugging in your iPhone to your Mac Pro?

I get one after every system update and go ahead and install. I tried once to not install and see if it could connect the iPhone and it did. However, I didn't try to sync which might be what the software update is for.
Also the iPhone can't connect to your Mac via BlueTooth. It's not designed to. It's WiFi that it connects with.
Give this a try: boot into Safe Mode according to How to use safe mode on your Mac and test to see if the problem persists. Reboot normally and test again.
NOTE 1: Safe Mode boot can take up to 3 - 5 minutes as it's doing the following;
• Verifies your startup disk and attempts to repair directory issues, if needed
• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)
• Prevents Startup Items and Login Items from opening automatically
• Disables user-installed fonts
• Deletes font caches, kernel cache, and other system cache files
NOTE 2: if you have a wireless keyboard with rechargeable batteries connect it with its charging cable before booting into Safe Mode. This makes it act as a wired keyboard as will insure a successful boot into Safe Mode.
