Many times the simple answer to the problem of mold build up in front load washers is the lack of good air circulation. Getting into the habit of leaving the front door and dispenser open when not in use will save you the hassle of dealing with mold in the first place.
If you already find yourself with a mold issue start with running a 1/2 cup of vinegar and then follow up with one Affresh tab. Repeat this step once a month combined with leaving the door open when not in use. It will take some time but it will get better. There are some extreme cases that you will need to replace your front door boot. Part number for this model is WH08X10022.