Adobe Photoshop CS5 does not recognise my scanner/All-In-One in Mac OS X. What should I do?


  • Mac OS X
  • Adobe Photoshop CS5
  • Scanning functionality - importing to Photoshop
  • Epson Scanner & All-In-One ranges


Adobe Photoshop CS5 no longer automatically installs the TWAIN plug-in it needs to recognise your scanner. Instead, the TWAIN plug-in is available via download from Adobe. Follow these steps to manually install the TWAIN plug-in:

  1. Quit Photoshop CS5.

  2. Download the optional Mac OS TWAIN plug-in from Adobe and read the accompanying support information. Adobe has made it available via the following TechNote article on the official Adobe website.
    • "Using TWAIN in Photoshop CS5 and CS4":


      This information is provided as is. Epson is not responsible for the content of third-party websites and the information may change without notice.

  3. Copy the TWAIN plug-in file to the Adobe Photoshop CS4\Plug-ins\Import-Export folder on your Mac OS X hard disk.

  4. Restart Photoshop to enable the plug-in.

We recommend using Photoshop in 32-bit mode as you must have a 64-bit version of the scanner driver to use the scanner in 64-bit Photoshop. If your Epson scanner does not have a 64-bit drivers available, run Photoshop in 32-bit mode in order to import the scanner.

For more information on Adobe Photoshop CS5 and how to run the software in 32-bit or 64-bit mode, we recommend viewing the following TechNote article on the official Adobe website:

On 32-bit Mac OS X, the TWAIN plug-in for Photoshop CS5 is not compatible with CS4. The Photoshop CS4 TWAIN plug-in is not compatible with CS5.

The Mac OS X TWAIN plug-in can be used when running Photoshop CS5 in 64-bit mode under Mac OS X Snow Leopard (10.6.x). It cannot be used in 64-bit mode under Mac OS X Leopard (10.5.x).


If you encounter any of the following problems when using the TWAIN plug-in with Photoshop CS5, please contact Adobe Systems Inc. for further support:

  • Photoshop or Epson Scan freezes or quits unexpectedly.

  • You are unable to close the Epson Scan window.

  • You see errors during the import.

  • The preview of the imported image, or the imported images itself, appears incorrect on the screen.

The Adobe Knowledgebase article (ID# kb405072) can be found here.

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