I had the same problem and the issue was with "Package Disabler". If you choose to disable all bloatware then it denies you access to the SD card too. Just re-enable all disabled packages in Package Disabler and this will work.
Me too! Also my number row is gone and I can't figure how to bring it back. Been googling all morning. For now I switched to Gboard and it has all the features. Seems like every update Samsung makes has turned out to be a downgrade.