HDI: Adding work around for Jupyter notebook known issue.

Author: mimig1

articles/hdinsight/hdinsight-release-notes.md

@@ -7,7 +7,7 @@ ms.reviewer: jasonh
 ms.custom: hdinsightactive
 ms.service: hdinsight
 ms.topic: conceptual
-ms.date: 01/08/2019
+ms.date: 01/24/2019
 ---
 # Release notes
 
@@ -60,3 +60,34 @@ HDInsight continues to make cluster reliability and performance improvements.
 
 ## Component version change
 No component version change for this release. You could find the current component versions for HDInsight 4.0 ad HDInsight 3.6 here.
+
+## Known issues
+
+As of January 24, 2020, there is an active issue in which you may receive an error when attempting to use a Jupyter notebook. Use the steps below to fix the issue. You can also refer to this [MSDN post](https://social.msdn.microsoft.com/Forums/en-us/8c763fb4-79a9-496f-a75c-44a125e934ac/hdinshight-create-not-create-jupyter-notebook?forum=hdinsight) or this [StackOverflow post](https://stackoverflow.com/questions/59687614/azure-hdinsight-jupyter-notebook-not-working/59831103) for up to date information, or to ask additional questions. This page will be updated when the issue is fixed.
+
+**Errors**
+
+* ValueError: Cannot convert notebook to v5 because that version doesn't exist
+* Error loading notebook An unknown error occurred while loading this notebook. This version can load notebook formats v4 or earlier
+
+**Cause** 
+
+The _version.py file on the cluster was updated to 5.x.x instead of 4.4.x.##.
+
+**Solution**
+
+If you create a new Jupyter notebook and receive one of the errors listed above, do the following:
+
+1. Open Ambari in a web browser by going to https://CLUSTERNAME.azurehdinsight.net, where CLUSTERNAME is the name of your cluster.
+1. In Ambari, on the left menu, click **Jupyter**, then on **Service Actions**, click **Stop**.
+1. ssh into the cluster headnode where the Jupyter service is running.
+1. Open the following file /usr/bin/anaconda/lib/python2.7/site-packages/nbformat/_version.py in sudo mode.
+1. The existing entry should show something similar to the following: 
+
+    version_info = (5, 0, 3)
+
+    Modify the entry to: 
+    
+    version_info = (4, 4, 0)
+1. Save the file.
+1. Go back to Ambari, and in **Service Actions**, click **Restart All**.