Moved to Technical support
I've gotten this message a few times with my external USB drive. You pretty much have to do what the message says. The safest thing to do is to hook the drive up to a Windows machine and run a chkdisk on it because it wasn't cleanly unmounted. The easiest thing to do is force the mount using the command in the message:
First, create a mount point in /media (preferably one without spaces in it because i think this will cause problems
mount -t ntfs-3g /dev/hdb1 /media/foobar -o force
But yeah, if this drive has important documentation on it, i would hook it up to a Windows machine, run chkdsk on it, and also change the name to something without spaces in it because "Local Disk 2" may cause problems.