attempted an AZ Login --user-device-code against an azure Stack instance. Code generation worked. Copied Device code to webpage then the following error occurs in powershell window

[XangoXCC]

This is autogenerated. Please review and update as needed.

Describe the bug

Command Name
az login

Errors:

'NoneType' object is not iterable
Traceback (most recent call last):
Temp\pip-install-yf22vmg2\knack\knack\cli.py, ln 215, in invoke
azure\cli\core\commands\__init__.py, ln 654, in execute
azure\cli\core\commands\__init__.py, ln 718, in _run_jobs_serially
azure\cli\core\commands\__init__.py, ln 711, in _run_job
Local\Temp\pip-install-yf22vmg2\six\six.py, ln 703, in reraise
azure\cli\core\commands\__init__.py, ln 688, in _run_job
azure\cli\core\commands\__init__.py, ln 325, in __call__
site-packages\azure\cli\core\__init__.py, ln 545, in default_command_handler
azure\cli\command_modules\profile\custom.py, ln 150, in login
site-packages\azure\cli\core\_profile.py, ln 240, in find_subscriptions_on_login
site-packages\azure\cli\core\_profile.py, ln 276, in _normalize_properties
TypeError: 'NoneType' object is not iterable

To Reproduce:

Steps to reproduce the behavior. Note that argument values have been redacted, as they may contain sensitive information.

• Put any pre-requisite steps here...
• az login --use-device-code

Expected Behavior

Environment Summary

Windows-10-10.0.18362-SP0
Python 3.6.6
Installer: MSI

azure-cli 2.6.0

Additional Context

[yonzhan]

add to S171

[yonzhan]

add to S172