Transfer files to external drive error -50

[zlloyd1]

I am trying to copy some video files to my external hard drive by USB, on my Macbook Pro laptop, and I am getting This operation cannot be completed because of an unexpected error (error code -50)....

Can anyone tell me what this means please??
Thanks in advance!!


For the record, I have not tried any specific troubleshooting, just confused by what this means.
Here is the error box.

 

[Fishrrman]

Could one or more of the files in question be corrupted?
That might cause the finder to abort the copying.

Important questions:
What FORMAT is the external drive in?
Is it HFS+, or is it something else?

Are you selecting multiple files and then trying to copy them all at once?
Try copying only a few files at a time, to see if this makes a difference.

 

[zlloyd1]

Could one or more of the files in question be corrupted?
That might cause the finder to abort the copying.

Important questions:
What FORMAT is the external drive in?
Is it HFS+, or is it something else?

Are you selecting multiple files and then trying to copy them all at once?
Try copying only a few files at a time, to see if this makes a difference.

Yes, I thought this myself at first, but it gave the same error box with each individual file as well....
It was confusing as can be, I did finally get it to work out, and it is HFS+ format. As stated, I got it fixed myself, in the end.
Still, thanks for the response!!