You mentioned keyboard shortcuts. If you're using the Alt+= shortcut and expecting it to open MathType, it ain't gonna happen (unless you change the keyboard shortcut assignment). MathType has its own keyboard shortcut, which is Ctrl+Alt+Q. There are other keyboard shorts to insert a MathType display equation and to edit an existing MathType equation. Refer to MathType Help for these.
If you have further problems, feel free to contact our Tech Support folks: support at dessci.com. When you write, be sure to give a full description of your problem, and include your MathType Product Key in all correspondence. (You can find your MathType Product Key by opening MathType, and clicking on Help > About MathType.)