In ProStructures for MicroStation or Power ProStructures the ProStructures Task might be available but no ProSteel or ProConcrete Tasks. It could be that the license options have not been selected.
There is a licensing dialog available in ProStructures on which the user specifies the license(s) they have. By default, it’s shown during startup—though it has a “Don’t show me this again” option on it. The dialog can also be opened with this icon from the task menu:
Or, from this pulldown menu entry:
Or you can use the keyin:
prostructure show license