I had a few issues running an external Maxtor drive via a USB hub, the disk was hanging and beeping on boot up. I traced this down to being due to the fact that the USB hub was not powered, and the drive was no getting enough power. That I resolved by using a powered USB hub, and the drive now boots fine and doesn't beep.

But! During the troubleshooting of the above I had to do a hard power-off of the whole system, and now when I try and access the disk I get the following message:

Error mounting /dev/sdb2 at /media/chris/6b237ae0-e75e-4990-a8dd-3cb5f1d2dcc6: Command-line `mount -t "ext4" -o "uhelper=udisks2,nodev,nosuid" "/dev/sdb2" "/media/chris/6b237ae0-e75e-4990-a8dd-3cb5f1d2dcc6"' exited with non-zero exit status 32: mount: mount /dev/sdb2 on /media/chris/6b237ae0-e75e-4990-a8dd-3cb5f1d2dcc6 failed: Structure needs cleaning
(udisks-error-quark, 0)

It's got 2 partitions on, one NTFS and one ext4; it seems the NTFS partition just fine, it's just the ext4 partition that seems to be having a problem.

Any ideas on how to troubleshoot and resolve this one? I have done a Google search on the error but not found anything useful so far...

TIA...

Did you try running fsck on the ext4 device?

Thanks - what's the complete command? I'm a noob in the linux world..

Given the output in your original post, the command would be:
The command should be run with /dev/sdb2 unmounted. The above command will attempt to automatically repair the filesystem on sdb2.