CBR Computed field, widget -> null

We downloaded CBR from TUWEL and added it as a module as requested. We further downloaded the neccessary dependency modules, as you can see on the second screenshot, all of them are enabled. However, when we are trying to create a CBR Computed field in the CBR content case, there is no widget to select (only null). Saving with null as a widget leads to an error. How can this be resolved? Thanks in advance.