While workig within a multipath dialogue workflow component, the embedded decision model begins its evaluation and process of data, but for some reason does not complete successfully and return program control back to the source dialogue component. This can really wreak havoc when troubleshooting, as no model validation errors are present. You are just left wondering why it won't finish.
Found wthin the emebedded decision model for the process, specifically in the options of the END component, under the Data Handling tab, there are specific data definitions that can be required to pass thru the process (embedded model) and be returned to the original workflow, or made optional. You should know the schema of the data you are trying to import when you declare your variables, or data types. This will allow you to control what you need, since, when using queried data from SQL or LDAP, the schema of the objects you are importing may have fields that may not be populated. The END component data handling is not aware of what portions of the schema may or may not have entries, and thus defaults to requiring each field to have data to continue. When it does not, the embedded model will not be able to complete as it does not have full information, and will not be able to return control back to the original workflow process.
In resolving this, we started out by making them all optional. We then started adding requirement back two to three at a time until it failed, thus isolating the required ones. It would be best, as stated above, to know your data sets and schemas beforehand, and plan accordingly.