Any reason you are following a Webcenter 126.96.36.199.3 document when you are using Jdeveloper 188.8.131.52 ? There might be steps which might have caused this .
Follow this instead - http://docs.oracle.com/cd/E25178_01/webcenter.1111/e12405/wcadm_documents.htm#BABDFFDC
I have followed the same steps.
I am not sure how to configure the repository connection in Jdeveloper.
27.2.2 How to Create a Content Repository Connection Based on the Oracle Portal Adapter
In Step 9: Connecting to the External application.
Can you give me an example? login URL format,ID Field name,authentication method.
I don't know there is a chapter particularly for this: Configuring Content Repository Connections - 11g Release 1 (184.108.40.206.3)
(Creating a Content Repository Connection Based on the Oracle WebCenter Adapter for SharePoint)
If you are sure you don't have a version conflict (WebCenter, but also SharePoint - The Oracle WebCenter Adapter for SharePoint extracts and searches content within a Microsoft SharePoint 2007 repository.) follow the manual in 25.2.3.x
Another question is if you did and it does not work - then you should contact support via Metalink.