Since Android 4.4 ("KitKat"), external apps are not allowed to write on any external storages (External SD-Cards, USB-Storages, etc.)

For Photo Mate, this means you may view and even edit images on that storages (when you edit, the XMP-Data is stored in the internal Photo Mate folder), but exporting images to that location is not possible. What if you want to save to your external storage, anyway?

• If you're using Lollipop, please access your SD-Card via Photo Mate. It will ask you to follow necessary steps to re-activate the writing permissions.
• If you don't have a rooted device nor lollipop and don't want to root it, you can create a folder-structure on your external storage which should look like:
  Photo Mate R3: Android/data/com.tssystems.photomate3 
  Photo Mate R2: Android/data/com.tssystems.photomate2
  You can then use this folder and also write to this folder in Photo Mate. Please use your system's file explorer to create this folder first
• If you have a rooted device, you can find several tools to unlock this limitation.

Important!

If you store your files in the external app directory, make sure you backup this directory before you uninstall the app! Android will delete this folder when you uninstall Photo Mate!