What computer operating system is your Premiere Elements 12 running on? And, have you updated 12 to 12.1 Update, using an opened project's Help Menu/Update? If you have not done that, please do so...solves an Expert workspace text style issue of 12 and has some undefined attributes.
What are the properties of this DSLR video? Your question cannot be given a proper answer without details.
Interlaced or Progressive
Pixel Aspect Ratio
The quickest way to the above might be for you to tell us the brand/model/settings for the camera that is recording the video. There are numerous
DSLR camera out there with a variety of modes and settings choices for record videos of different formats. We need to be sure that your choice of recording is supported by Premiere Elements.
Please review and consider and then we can decide what next.