Printer Driver in macOS Sierra
Yeah, that installer is from 2011 so it may not work anymore... The following site suggests they dropped support for it in 10.10:

http://www.dell.com/support/article/us/en/19/SLN294375/EN

That being said, does it work if you select a generic driver?

Looks like people have used the SAMSUNG ML-191x 252x SERIES driver with success previously:  http://en.community.dell.com/support-forums/peripherals/f/3528/t/19450382