The custom XSLs previously available in 11g version are now available in the 12c version. To make sure that the source/target mapping feature is not lost, do not copy the XSL as is from the 11g version to the 12c version. Instead, manually merge those changes from the 11g version of XSL to the 12c version of XSL.

Redeploy the modified processes either from JDEV or using the custom DP file.