I don't know about that particular disk, but a relatively common copy-protect scheme was to damage the disk in one or more locations. Upon launch, the program would check for the ability to write to the damaged area. A successful read-write-verify operation would cause the program to quit.

The damage was fairly obvious to the naked eye, so you can readily check whether this method was used in your case. Just open the shutter and rotate the disk. Look for an obvious burn mark or something similar. To (attempt to) make a copy, note the location of the damaged area with as much precision as you can, and use a utility knife to make a matching defect in the target floppy. Rerun your copy operation, and see what happens. You may not succeed on the first try, but with care you should be able to get there eventually.