Many phones with Android 6.0 Marshmallow has disable ability to use SD card as extension of internal storage. That limits number of apps we can install on the phone.

However, there is quick fix which allows to enforce SD card to work as Internal Storage extension.

First you need to install Android SDK Platform Tools.

Once you have it, you need to enable Developer Mode on the phone:

  1. Go to Settings,
  2. Scroll down and tap on About phone,
  3. Locate Build number option (on some phones in Software info section),
  4. Keep tapping on Build number until you see note You are now a developer!,
  5. Go back to Settings and locate Developer options,
  6. Enable option Enable OEM unlock,
  7. Enable option USB debugging.

Once it’s done you can connect phone to PC using USB cable and start Command Prompt.

In Command Prompt go to folder where you have Android SDK Platform Tools installed and perform following tasks:

E:\AppData\Android\SDK\platform-tools>adb shell
shell@m253:/ $ sm list-disks
shell@m253:/ $ sm set-force-adoptable true
shell@m253:/ $ sm partition disk:179,128 private
shell@m253:/ $ sm set-force-adoptable false
shell@m253:/ $
Remember to adjust disk:179,128 parameter, if you have different numbers for your SC Card.
Once all command are done disconnect USB cable and reboot your phone. It might take longer than usual to boot your phone. !!! THIS IS IMPORTANT AND HAS TO BE DONE IN ORDER TO COMPLETE PROCEDURE WITH SUCCESS !!!

Now enjoy expanded Internal Storage.