The client application should use **Java version 8 or higher** to connect to the Denodo Platform 8.0.
Since the IBM Infosphere Datastage version 11.5 cannot be updated to use Java 8. If possible, you could upgrade IBM Infosphere Datastage to higher versions that use Java 8 to access the Denodo Platform.
You can have a look at the Knowledge Base article [Java versions supported by the Denodo Platform](https://community.denodo.com/kb/en/view/document/Java%20versions%20supported%20by%20the%20Denodo%20Platform) for more information.
Hope this helps!