note

Author: ealsur

articles/cosmos-db/troubleshoot-changefeed-functions.md

@@ -3,7 +3,7 @@ title: Troubleshoot issues when using Azure Functions trigger for Cosmos DB
 description: Common issues, workarounds, and diagnostic steps, when using the Azure Functions trigger for Cosmos DB
 author: ealsur
 ms.service: cosmos-db
-ms.date: 07/17/2019
+ms.date:03/13/2020
 ms.author: maquaran
 ms.topic: troubleshooting
 ms.reviewer: sngun
@@ -47,6 +47,10 @@ This means that either one or both of the Azure Cosmos containers required for t
 
 The previous versions of the Azure Cosmos DB Extension did not support using a leases container that was created within a [shared throughput database](./set-throughput.md#set-throughput-on-a-database). To resolve this issue, update the [Microsoft.Azure.WebJobs.Extensions.CosmosDB](https://www.nuget.org/packages/Microsoft.Azure.WebJobs.Extensions.CosmosDB) extension to get the latest version.
 
+### Azure Function fails to start with "PartitionKey must be supplied for this operation."
+
+This error means that you are currently using a partitioned lease collection with an old [extension dependency](#dependencies). You need to upgrade to the latest available version. If you are currently running on Azure Functions V1, you will need to upgrade to Azure Functions V2.
+
 ### Azure Function fails to start with "The lease collection, if partitioned, must have partition key equal to id."
 
 This error means that your current leases container is partitioned, but the partition key path is not `/id`. To resolve this issue, you need to recreate the leases container with `/id` as the partition key.