Macbook Pro won't read Toshiba external drive

[tximacusr]

I was using the Toshiba external drive and shut down the Macbook before ejecting the external drive, which I usually do. About two hours later I restarted the computer with the external drive still attached and got the following attached message.

It won't read the external drive now. I've had the drive for about a year and just started to use it frequently. Since it won't read it, is there any way to use a Macbook app to move the files from the external to the Macbook? Thanks in advance!

 

[maflynn]

Looks like shutting it down, before it was ejected caused some corruption. Did you try to run some tests on it with Disk Utility?

I wonder if you're only option is to reformat it and start over.

If you can, plug it into another computer and see if the issue returns

 

[tximacusr]

Looks like shutting it down, before it was ejected caused some corruption. Did you try to run some tests on it with Disk Utility?

I wonder if you're only option is to reformat it and start over.

If you can, plug it into another computer and see if the issue returns

Disk Utility is grey, won't let me work on it.
I don't have another computer, will try it with a friend.