When you attempt to run two modules containing identical output alias names, the Text Analytics engine throws a ModuleLoadException, indicating that there was an error in loading the given set of modules.
ModuleLoadException with an error message "Nickname <conflicting alias name> appears twice in operator graph spec"
The modules you attempted to run contain conflicting output alias names.
Resolving the problem
1) Verify that the modules you are attempting to run were designed to be run together. If the modules were designed to provide different implementations of same type of entity and the output aliases were intentionally made identical so as to ensure consistent output names for semantically similar views, then they were not designed to be run together. In such a case, understand the valid set of modules that should be run together.
2) If the modules were designed to be run together, then modify the output alias names such that they are different from each other.
It is a good practice to validate modules before running them. You can invoke the Text Analytics API OperatorGraph.validateOG() to verify that the given set of modules can be successfully loaded together. You can also use the Explain Module feature of InfoSphere BigInsights Text Analytics tool to examine if there are any conflicting alias names in the list of modules to run.