Hi,
If you cannot create objects in your Use Case diagram, it's probably because your diagram has been created without a 'context'...
In Modelio 2.2.0, the 'context' corresponds to the element to which the diagram will be associated. To select this context, simply drag and drop the desired element(for example, a package), or click on it to switch to ‘picking’ mode, or else use the CTRL-Space shortcut to obtain a list of available elements.
Certain diagrams can be created without a context, (Class, Deployment, Object and UseCase) but these diagrams without context will only allow elements to be unmasked but not to be created in them. That's what happen to you I guess...
This problem/confusion has been fixed in the latest version of Modelio (
2.2.1), now the context of a diagram is its owner element. ‘no-context diagrams’ don’t exist any more...
See Modelio 2.2.1 change log for more information:
forge.modelio.org/projects/modelio/wiki/Modelio_221
Best regards,
cde