can't set up a new password protected dmg file

I follow all the steps in Disk utility, including encryption, and password, read & write option, etc. But when I try to create the image, I get this msg:

"Operation Failed with status 28.". I can't find any help online.

I'm using Sierra version 10.12.2 on my Mac mini.

Any help out there?

Found the problem. The drive I was intending to use was not highlighted on the disk utility. When I did so, all worked. Thanks anyway.

Once again persistence wins the day. Glad you got thet sorted out.