[Q] 64GB version shows only 12GB? topic

I've got a 64GB MI4 and the phone can only access some of it. Sorry the screenshots are in german.

I've tried doing a full wipe and installing the newest ROM and I tried doing a reset with CWM and installing sMIUI, but the memory is not getting bigger :(

The last two screenshots are the only one that suggest that I could have more memory, but I don't know what I have to do to get it working.

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