Marshmellow issue with large SD card as internal storage (this was posted in the thread insufficient storage even with marshmallow sd card formatted for internal space and plenty of space which is a discussion about this same problem, but for some reason this got deleted... dont understand this.  Now I opened a new question)

Today I inserted a brand new 64GB fast SD card (Sandisk extreme U3) in my MotoG 2nd generation, as I was constantly hitting the internal storage barrier. I formatted it as "internal storage" also called Adopted storage I believe.

I was expecting to see a total size of 64 GB of "memory" to be available, and not having to bother anymore with choosing between internal mem and SD cards. So I am now still puzzled why I still see both separate, and still hit the limits on storage space... I thought Android would handle this fully in background, so the user would see 1 big memory. What I don't understand is that I still get the "not enough space" error and why then I would have to manually move apps or data between Internal memory...

When I check the storage, I see Android 2.5 GB, Internal memory 4.6 of 5.5 used, Sandisk SD card almost all free (58GB)

anyone can help ?
Apps can't be stored on SdCard. The only way to do that is rooting the phone and use apps like Link2sd or adopting SD card if you have Android 6+. Here is how to do it.