- If you really want to like El Capitan but can’t actually complete the download due to error messages, your current version of Yosemite is probably causing trouble. Remember that for a new download, especially a large one, Mac OS X needs to shut down various programs and processes. If Yosemite is already working on other updates or various ongoing processes, it may produce error messages instead of completing El Capitan.
- One of the easiest solutions for this problem is to fully reboot your computer and clear any current issues that Yosemite is experiencing. Visit theApple Menu (the button in the top left of your screen with the apple logo), and select the option Restart. Sometimes if Yosemite has really hit a wall this will freeze your computer instead of restarting it. If this happens, press Control key-Command key (⌘) -Power button at the same time. This will force the restart – just be sure that your programs are closed and your data saved before you attempt this.
- If restarting doesn’t work,try opening in safe mode to stop any annoying apps. Safe mode allows you to open a limited version of the Mac OS X that can be very useful when locating problematic apps or other issues with your computer. To begin, go to the Apple Menu and select Shut Down. You can also hold down the power button to force a shutdown if necessary. Wait until your Mac is completely turned off, then wait about 10 seconds and press the power button to start your computer up again. Pay careful attention: When you hear the Mac startup sound as the computer gets ready to launch, hold down the Shift key. A gray Apple logo screen will appear – when it does, release the Shift key. This will start your computer in safe mode.
- If Yosemite runs correctly in safe mode, then you probably have a problem with an app or startup item. Disable all your startup items by going to System Preferences, Users & Groups, and selecting your User ID. Under Login, you can choose what apps automatically start with Yosemite. Disable all of them and try installing El Capitan again.
- It’s important to save all your important data through a site or an external hard drive before you start to install El Capitan. Things can go wrong, and if they do you may lose valuable data. Always be safe instead of sorry.