# Adopting Oxygen (4.7) mechanisms and APIs

This section describes changes that are required if you are trying to change your 4.6 plug-in to adopt the 4.7 mechanisms and APIs.

1. Pre-built Lucene indexes should be updated

## 1. Pre-built Lucene indexes should be updated

What is affected: Clients supplying pre-built Lucene help indexes.

Description: We have updated the Apache Lucene search engine to Lucene 6.1.0. This means that the indexes built with 3.5.0 will not be readable anymore. See Lucene Change Log for details.

Action required: Clients should:

- Re-build their indexes with Lucene 6.1.0 and supply them as before