Microsoft Bot Framework SDK V4 was released in September 2018, and since then we have shipped a few dot-release improvements. As announced previously, the V3 SDK is being retired with final lifetime support ending on December 31st, 2019. Existing V3 bot workloads will continue to run without interruption. We have no plans to disrupt any running workloads.
Accordingly, Microsoft will discontinue the ability to create new V3 Bots via Azure Portal on July 1st, 2019. CLI tool support for new V3 Bot creation will discontinue on August 1st, 2019.
We highly recommend that you start migrating your V3 bots to V4. In order to support this migration we have produced migration documentation and will provide extended support for migration initiatives (via standard channels such as Stack Overflow and Microsoft Customer Support).
For more information please refer to the following references: