Internal HD on Mac is not full, only half. Trying to copy to external hard drives, but cannot. I get a full hard drive message

Solution
You are saying you are copying TO the external drive, but you said the internal drive was half full, which is a bit backwards. Did you check those external drives? The internal drive not being full does not matter if you are copying to another drive. Are they maybe write protected or have a file system the MAC can't read? Test them on another computer.
You are saying you are copying TO the external drive, but you said the internal drive was half full, which is a bit backwards. Did you check those external drives? The internal drive not being full does not matter if you are copying to another drive. Are they maybe write protected or have a file system the MAC can't read? Test them on another computer.
 
Solution