Just returned from a very intensive 4-day vacation with a bunch of photographs (over 800) on a 64 GB card. Too tired, I've put the card in the reader, put the reader in the computer USB, and… got this!

Unable to mount 64 GB volume

That sounds like a good time to…

PANIC!

^{Edvard Munk — Scream}

Fortunately, Internet keeps the experiences of those guys who had the same problem, and who solved the problem. This solution is successfully tested on Ubuntu 14.04 & Mint 17.3

If you are using one of those Linux systems, you can enable exfat-fuse and exfat-utils packages that are present in Universe repository.

Enabling commands are:

sudo add-apt-repository universe

Update your software list using:

sudo apt-get update

Now you can install it using:

sudo apt-get install exfat-fuse exfat-utils

Enjoy.

If you have a better solution, please share&improve this answer.

If you don’t, you can thanks for this solution to the guy who signs up like g_p at https://askubuntu.com/

Universal Basic Income