It's odd. All sources are selected and I have no custom motivation entries at all.
I tried unselecting all sources other than one each of the CRBs (the minimum you need for things to work properly), and each CRB by itself worked fine for both adding and for randomizing. That error sounds more like it can't find any motivations and that the combobox's are empty. Are you running from the web install or the ZIP install?
Hmmm..... I did the Web install. Let me try the zip and see if get the same.