Hardware

If the shutter wouldn't close, that indicates physical damage to the disk casing. It is possible that after you removed the tape, the disk drive may not have been able to open the shutter. You might try physically removing the shutter and then trytre-accessing the disk (and dumping the diskette after getting the data off).

If you still can't access any data on the floppy, the physical damage may have extended to the media itself. Barring access to any data recovery software, the data is probably lost (unless you want to spend the bucks to send it to a data recovery service).

In addition to Tims answer if your machine won't read it clearly, try a couple others, I've found calibration can be off a little between machines and sometimes trying a different one will read where another will not. Good Luck! Make sure virus protection is active!!