• SqlPackage or DacFx Version: 15.0.5120.2

• .NET Framework (Windows-only) or .NET Core:

• Currently installed "classic" .NET Versions in the system:
  2.0.50727.4927 Service Pack 2
  3.0.30729.4926 Service Pack 2
  3.5.30729.4926 Service Pack 1
  4.0.0.0
  4.8.09032

• Environment (local platform and source/target platforms):

Steps to Reproduce:

1. Create a Managed Instance in Azure

2. Create a database in the managed instance

3. Use the following script to generate objects within the database
   CREATE MASTER KEY ENCRYPTION BY PASSWORD = 'dfgsdfgshrhhnfg_344f';
   GO
   /* specify credentials to external data source

   • IDENTITY: user name for external source.
   • SECRET: password for external source.
     */
     CREATE DATABASE SCOPED CREDENTIAL SqlServerCredentials
     WITH IDENTITY = 'Clive', Secret = '';
     GO

   /* Make sure Polybase is enabled */
   
   sp_configure 'POLYBASE enable',1
   reconfigure
   go
   

   CREATE EXTERNAL DATA SOURCE SQLServerInstance
   WITH (
   LOCATION = 'sqlserver://we-server.database.windows.net',
   DATABASE_NAME = N'***_NDW_TEST',
   -- PUSHDOWN = ON | OFF,
   CREDENTIAL = SQLServerCredentials,
   TYPE = RDBMS
   );
   GO

CREATE EXTERNAL TABLE [dbo].[all_dm_exec_requests]([session_id] smallint NOT NULL,
[request_id] int NOT NULL,
[start_time] datetime NOT NULL,
[status] nvarchar(30) NOT NULL,
[command] nvarchar(32) NOT NULL,
[sql_handle] varbinary(64),
[statement_start_offset] int,
[statement_end_offset] int,
[cpu_time] int NOT NULL)
WITH
(
DATA_SOURCE = SQLServerInstance,
SCHEMA_NAME = 'sys',
OBJECT_NAME = 'dm_exec_requests'
)

4. Attempt to Extract Data Tier Application from SSMS
5. Fails with the following TITLE: Microsoft SQL Server Management Studio

Could not extract package from specified database.
Error 0: An error occurred while attempting to reverse engineer elements of type Microsoft.Data.Tools.Schema.Sql.SchemaModel.SqlExternalDataSource: Unsupported external data source type '1'.
(Microsoft.SqlServer.Dac)

ADDITIONAL INFORMATION:

Unsupported external data source type '1'. (Microsoft.Data.Tools.Schema.Sql)

BUTTONS:

OK

Did this occur in prior versions? Yes

(DacFx/SqlPackage/SSMS/Azure Data Studio)