Some Mac users say that they can't download programs from other website except Mac App Store, or they may can't be opened the download file. When they click on the download file, it says 'xxx can't be opened because it is from an unidentified developer'.For example. Head to the Mac App Store, locate your installation file in the Purchases tab, and download it. Next, if you run OS X El Capitan or later, you will need to disable a feature known as System. In the event of a serious problem with your Mac, you may need to reinstall your Mac operating system. There's a simple way to do this using your Mac Recovery partition or via Mac Internet Recovery.
When you try to start Adobe Photoshop or Adobe Photoshop Elements on Mac OS, the application returns the following error:
'Some of the application components are missing from the Application directory. Reinstall the application.'
Solution 1: Start Photoshop from the Applications folder.
If you moved the Photoshop application file from its default location, and you start Photoshop from that location, then do the following:
1. If the error window is still open, then click OK to close it.
2. In the Finder, move the Photoshop application file from its current location to the following location:
- Photoshop CS4: //Applications/Adobe Photoshop CS4
- Photoshop CS5: //Applications/Adobe Photoshop CS5
- Photoshop Elements 8: //Applications/Adobe Photoshop Elements 8
- Photoshop Elements 9: //Applications/Adobe Photoshop Elements 9
3. Double-click the Photoshop application icon in the Photoshop folder to start Photoshop.
4. (Optional) For more convenient access to Photoshop in the future, control-click the Photoshop icon in the Dock and select Keep In Dock.
Solution 2: Remove the Locales folder and repair the installation of Photoshop.
- In the Finder, navigate to the Photoshop application folder.
- If the Locales folder is not listed within the application folder, then skip to Step 5.
- If the Locales folder is listed within the application folder, then drag the Locales folder to the Trash.
- Start the installer for Photoshop or your edition of the Adobe Creative Suite.
- If you purchased boxed software, then insert the installation DVD-ROM into your computer's DVD drive.
- If you purchased downloadable software from the Adobe Online Store, then double-click the disk image (.dmg) file or files that you downloaded. (If you no longer have the downloaded disk image file or files, then log in to your account at www.adobe.com/membership to download the installer.)
- Double-click the file named Setup on your installation DVD-ROM or disk image.
- In the installer window, select Adobe Photoshop in the Installed Products list.
- (Optional) Deselect Adobe AIR, Adobe Media Player, Adobe Device Central, Adobe Drive, Adobe Extension Manager, Adobe ExtendScript Toolkit, and Adobe Fonts All.
After the installation is complete, verify that the installer reported no errors. If the installer reported an error, see the following documents:
- Troubleshoot installation problems with Adobe Creative Suite 4 or Point Products on Mac OS X (kb403986)
- Troubleshoot CS5 installation (cpsid_82827)
- Troubleshoot installation problems | Adobe Premiere Elements 9 | Photoshop Elements 9 | Mac OS (cpsid_85844)
Note: Adobe also recommends that you install all available updates for your product. To download and install updates, start Photoshop, choose Help > Updates, and follow the onscreen instructions. Alternatively, go to http://www.adobe.com/downloads/updates/ to download and then manually run the update installer.
Reinstall from macOS Recovery
macOS Recovery makes it easy to reinstall the Mac operating system, even if you need to erase your startup disk first. All you need is a connection to the Internet. If a wireless network is available, you can choose it from the Wi-Fi menu , which is also available in macOS Recovery.
1. Start up from macOS Recovery
To start up from macOS Recovery, turn on your Mac and immediately press and hold one of the following sets of keys on your keyboard. Release the keys when you see an Apple logo, spinning globe, or other startup screen.
Command (⌘)-R
Reinstall the latest macOS that was installed on your Mac (recommended).
Option-⌘-R
Upgrade to the latest macOS that is compatible with your Mac.
Mac Reinstall A Required Download Is Missing
Shift-Option-⌘-R
Reinstall the macOS that came with your Mac, or the closest version still available.
You might be prompted to enter a password, such as a firmware password or the password of a user who is an administrator of this Mac. Enter the requested password to continue.
When you see the utilities window, you have started up from macOS Recovery.
2. Decide whether to erase (format) your disk
You probably don't need to erase, unless you're selling, trading in, or giving away your Mac, or you have an issue that requires you to erase. If you need to erase before installing macOS, select Disk Utility from the Utilities window, then click Continue. Learn more about when and how to erase.
3. Install macOS
When you're ready to reinstall macOS, choose Reinstall macOS from the Utilities window. Then click Continue and follow the onscreen instructions. You will be asked to choose a disk on which to install.
- If the installer asks to unlock your disk, enter the password you use to log in to your Mac.
- If the installer doesn't see your disk, or it says that it can't install on your computer or volume, you might need to erase your disk first.
- If the installer is for a different version of macOS than you expected, learn about macOS Recovery exceptions.
- If the installer offers you the choice between installing on Macintosh HD or Macintosh HD - Data, choose Macintosh HD.
Mac Restore A Required Download Is Missing
Please allow installation to complete without putting your Mac to sleep or closing its lid. During installation, your Mac might restart and show a progress bar several times, and the screen might be empty for minutes at a time.
If your Mac restarts to a setup assistant, but you're selling, trading in, or giving away your Mac, press Command-Q to quit the assistant without completing setup. Then click Shut Down. When the new owner starts up the Mac, they can use their own information to complete setup.
macOS Recovery exceptions
The version of macOS offered by macOS Recovery might vary in some cases:
- If macOS Sierra 10.12.4 or later has never been installed on this Mac, Option-Command-R installs the macOS that came with your Mac, or the closest version still available. And Shift-Option-Command-R isn't available.
- If you erased your entire disk instead of just the startup volume on that disk, macOS Recovery might offer only the macOS that came with your Mac, or the closest version still available. You can upgrade to a later version afterward.
- If your Mac has the Apple T2 Security Chip and you never installed a macOS update, Option-Command-R installs the latest macOS that was installed on your Mac.
- If you just had your Mac logic board replaced during a repair, macOS Recovery might offer only the latest macOS that is compatible with your Mac.
If you can't get macOS Recovery to offer the installer you want, you might be able to use one of the other ways to install macOS.
Other ways to install macOS
- You can also install macOS from the App Store or Software Update preferences. If you can't install macOS Catalina, you might be able to install an earlier macOS, such as macOS Mojave, High Sierra, Sierra, El Capitan, or Yosemite.
- Or create a bootable installer disk, then use that disk to install macOS on your Mac or another Mac.