Mount grayed out for encrypted disk in Recovery Mode

I am running the latest El Capitan on a mid-2015 MacBook Pro. The internal boot drive is encrypted with FileVault. The issue I am seeing is that when I boot in Recovery Mode so that I can run First Aid on the boot volume, the "Mount" button is grayed out when I select the logical volume. Anyone know what I am doing wrong or what the problem might be?

Thank you.