I don't even use Linux Mint anymore but just created an account here anyway to say THANK YOU! This issue has been bugging me for months on both Debian Stretch and Gentoo (but not on Debian Jessie, I guess since it uses an older kernel version) and this finally fixed it. You're my rainbows hero!You MIGHT try this. It sounds similar to a problem I had with an external USB Touro drive. The system would hang on boot for like 20 seconds when it was attached and sometimes randomly hang afterwards. We'd have to investigate more to be absolutely sure and I might be off line for a while.
1) Get YOUR device Vendor_ID and Product_ID with:
$ lsusb -v
2) Create file /etc/modprobe.d/ignore_uas.conf with:
options usb-storage quirks=0x4971:0x1023:u
(these are example ID's, use YOURS here)
3) Regenerate your initial ramdisk:
$ sudo update-initramfs -u
4) Reboot computer.
You can always remove this file if it doesn't work. And then do "sudo update-initramfs -u" and reboot again and it's gone.
