Can't access mixer view in session drummer 3

Hi all,
New to this forum, and hope someone can help with this. When I open session drummer 3 ( I have sonar 8.5 producer) the window that comes up (showing the drum kit) only shows part of the whole screen I should be able to view. The screen is cut off right at the edge of the drumkit button in the top right corner, so that I can't see, or press, the mixer button to open it up. Is there something simple I'm missing here? Or a different way to open up the mixer? I tried contacting cakewalk support, and got no response (weeks ago). Thanks for any suggestions.

It doesn't matter how I open it. As I stated, the window with the drum kit comes up (that works either way) - I can have it floating above the other window - or lock it - but for some reason, it is like the window needs to be stretched out to show more of what is in the window, but it is stretched to its max, and still only shows most, but not all of the kit, and only part of the drumkit/mixer button. I can't get into the mixer part of the program, because the button, in the top right corner, only shows the drumkit part of the button. I took a picture of it, but can't figure out how to insert it into this post.

I have looked at some of the videos suggested, and they are very helpful, but there is obviously a glitch in my program that doesn't allow a full unobstructed view of the drumkit window. I can't follow very far in the video because as soon as he gets to the section where he says "click on the mixer button" I am at a standstill.

The program itself works fine. I can load the kits, and make patterns etc, but I can't insert  all of the seperate midi tracks to individual tracks, so that I can have separate recordings of each part, eg 1 track for snare, one for kick etc., as this is done through the mixer view.