Lag when entering password during install

Whenever I enter the password during install, everything freezes and the mouse disappears for a couple of seconds.

Ubuntu Mate 16.04 64 bit (dvd iso). This occurs whether I install directly or install from the live desktop.

Your DVD might be faulty. You could try to burn another one at the lowest possible speed (this causes less issues) or try with a USB instead. I have had a faulty installation as well and a change of medium has solved the issue for me. Also make sure that you have verified your iso.images.

Did you follow this advice when creating your disk?: