For processing a new data set it is recommended starting with an empty workspace. Either one of the existing workspaces is cleared with the 
button, or a new workspace is created with the + button in the upper right. In the latter case, all configurations of the currently active workspace will be copied.
As the first thing, an adequate model should be selected from the menu Pixelwise/Model or from the option list in the workspace tab.
The reason is that the available user interface elements are adjusted to fit the requirements of the model.
How To Continue
After model selection, the actual data processing can start with image loading described below.