SDcard support on smartphone

My new Redmi 3 Pro support up to 128GB sdcard, but when inserting newly purchased sdcard UHS-I 64GB, it was not detected in the file manager.
I guess this problem might also occur on other brand/type of smartphone.
First check whether the phone actually support 64GB external storage or something smaller.
Then do a format using the phone, not a PC format.
To do this, go to setting/storage.
Tap on sdcard. On xiaomi, this will bring a pop up, swipe down and tap on the pop up to format sdcard.
On stock android, first un-mount the sdcard by tapping on external storage.
The option to format is greyed out when the sdcard is mounted. SDcard is automatically mounted when inserted and detected by android.
This should be a straightforward solution. Let me know if you find further trouble with sdcard not detected.

yogi@yours.com