Update POST.md

docs/en/Blog-Posts/2020-10-15 v3_3_Preview/POST.md

@@ -178,6 +178,10 @@ We have good news for the ABP Commercial Blazor UI too. We have implemented the
 
 There are still missing features and modules. However, we are working on it to have a more complete version in the next release.
 
+#### Breaking Changes on the Blazor UI
+
+There are some breaking changes with the Blazor UI. If you've built an application and upgrade it, your application might not properly work. See the [ABP Commercial Blazor UI v 3.3 Migration Guide](https://github.com/abpio/abp-commercial-docs/blob/dev/en/migration-guides/blazor-ui-3_3.md) for the changes you need to do after upgrading your application.
+
 ### Multi-Tenant Social Logins
 
 [Account module](https://commercial.abp.io/modules/Volo.Account.Pro) now supports to manage the social/external logins in the UI. You can **enable/disable** and **set options** in the settings page. It also supports to use **different credentials for the tenants** and it is also **configured on the runtime**.