Problem:

When using the composite tools of analysis tools in the enterprise menu,  a window which represents a data structure displaying

             Ex:     stack

                       Children of data item

                       Analyze a statement

                       Union

                        {

                                   Stack

                                    Parent data items

                          }

                         Union

                          {

                                      Stack

                            }                            

                                   Etc...

      Even though specific properties are set as well as the tools, an error message saying "Tool stack returned error status" and next error message   "This tool requires an input set to operate".

What do these messages mean?

Resolution:

This particular composite tool requires an input set, once that input set is dropped on this composite tool, it will give back the appropriate set of information.  If the Composite tool has an analysis tool that requires a set but none is provided, the subsequent tools will deliver errors based on what it is expecting.

For this example, stack, will either Put, Push, Peek or Discard the set, it will then follow those instructions to "Children of data item", which is going to produce another set to be put in "Analyze a statement" and then UNION with the resulting set of "Parent Data items" and that's how it works.  If no Set is dropped on this tool and it's just "double clicked" on the tool, then the errors occur.