Why is R2016b install media slightly stained.

During I install R2016b version by install media(DVD), some install error and re-try are occurred. I checked the DVD surface and found something to be stained and to be damaged. They looks like something mark that other DVD leave. And the DVD package has not been opened. I'm afraid if my R2016b install data is completely correct. Also some MATLAB have damaged DVD. Please check all DVD media to be prepared!!

[Walter Roberson]

The install process does CRC checks to be sure that the packages are not corrupted.