WD My Passport Se 1TB Stopped Backing up!

What should I do? my last back up was September 28 and August 16 using only 1 backup version on the settings. I thought i just need to wait for a month for it to start backing up a new version of the files but it stopped. 

CAn anybody help me with this? Thanks!

it will depend on your configuration, it should do it automatically every time that the computer goes idle.

check the settings of the software to see if is setup like that.

How do i do that?