Update index.md (dotnet#17037)

Rick-Anderson · web-flow · commit f2b86e38cd97 · 2020-02-18T20:30:14.000-08:00
* Update index.md

* Update index.md
diff --git a/aspnetcore/security/data-protection/compatibility/index.md b/aspnetcore/security/data-protection/compatibility/index.md
@@ -9,3 +9,4 @@ uid: security/data-protection/compatibility/index
 # Compatibility in ASP.NET Core
 
 * [Replacing ASP.NET \<machineKey> in ASP.NET Core](xref:security/data-protection/compatibility/replacing-machinekey)
+* `Microsoft.AspNetCore.DataProtection` 3.1 not compatible with Azure function apps. For more information, see [this GitHub issue](https://github.com/Azure/azure-functions-host/issues/5447)

Original file line number	Diff line number	Diff line change
`@@ -9,3 +9,4 @@ uid: security/data-protection/compatibility/index`
`9`	`9`	`# Compatibility in ASP.NET Core`
`10`	`10`
`11`	`11`	`* [Replacing ASP.NET \<machineKey> in ASP.NET Core](xref:security/data-protection/compatibility/replacing-machinekey)`
	`12`	+* `Microsoft.AspNetCore.DataProtection` 3.1 not compatible with Azure function apps. For more information, see [this GitHub issue](https://github.com/Azure/azure-functions-host/issues/5447)