Quicktime "Switching transport" issue

Which version of Mac OS X does your computer have running in it? What model MB/Pro do you have?

{Are you running Snow Leopard 10.6.8? If so, you'd have to use the Quicktime Player application to change settings, according to what I've read, as there would not be a Quicktime icon in the System Preference panels. You'd use the Quicktime Player menu to Register a Pro Key, for example.}

If your computer is running OS X 10.6.8 you could look into the install DVD and reinstall QT from there, a way to install just that should exist without a complete reinstall. (Not sure if this restores a lost QT icon in other OS X versions.) Any updates are another matter... Mac App Store?

If for some other reason your icon to Quicktime is due to someone removing that part of Quicktime from a special library folder where all the icon items for System Preferences is located, you may have to search help in your OSX to see how to restore System Preference icons. It may be simple, in an admin account.

The actual files that provide System Preference icons -- that is in: /System/Library/PreferencePanes Below is a list of what should be in Leopard 10.5.8, and in 10.6.8 there would not be a Quicktime icon in that preference icon location. These are not just icons.

In OS X 10.5.8: here is a list of files in that folder: Accounts, Appearance, Bluetooth, DateAndTime, DesktopScreenEffectsPref, DigiHubDiscs, Displays, Dock, EnergySaver, Expose, FibreChannel, Ink, Internet, Keyboard, Localization, Mac, Network, ParentalControls, PrintAndFax, QuickTime, ScreenSaver, Security, SharingPref, SoftwareUpdate, Sound, Speech, Spotlight, StartupDisk, TimeMachine, Trackpad, UniversalAccessPref.

Many missing icons in System Preferences?

(ones supposed to be there in 10.6.8 & before, or others)

https://discussions.apple.com/thread/2502231?tstart=0

What version Quicktime player is in the Applications folder? QT 7 v 10?

Depending on vintage of OS X, there are things that Quicktime

doesn't do anymore, or well, & some helper applications exist.

Good luck & happy computing! 🙂

a PS to the above:

If nothing else, and an issue does exist, you may need to try some extensive system maintenance to the tune of a variety of items, some hard core ones appear here... if your computer doesn't play well after some basic restarts with SafeBoot, repair disk permissions, quit disk utility, restart. etc.

Check Console's Log files, they may tell something about what happens when Quicktime is called; maybe it's hiding out after new years, and won't take a call. Or they are in it together. Aiding and abetting? LOL

• Resolve startup issues and performance disk maintenance with Disk Utility and fsck

https://discussions.apple.com/thread/2502231?tstart=0

Maybe some of this may help.

Good luck & happy computing! 🙂