It's possible that you've changed the zoom level of your project. You can see current zoom level in the lower right corner of the screen. In zoom mode, you can see a wider view of the project, but controls are disabled. To return to normal zoom, click View>ZoomToNormal. This should make the controls accessible again.
The keyboard shortcut for "Zoom to Normal" is Ctrl + Shift + F6.
Example screenshot of the status bar for a project shown at a 95% zoom level:
A common misunderstanding is that the zoom percentage number in the status bar is showing your project's MIPS utilization. This FAQ describes where you can find your MIPS and memory utilization information for the SigmaDSP you are using in your project.
This FAQ was generated from the following discussion: I can't control any of the knobs or sliders in my SigmaStudio project. What's wrong?