We are updating the SmartThings web login on Wednesday, October 10th. Starting Wednesday, you will need to choose to sign in with a Samsung account or, if you have not yet migrated, a SmartThings account.
This change will not impact either the SmartThings or SmartThings Classic app. This will affect logging into the IDE and authorization of integrations such as Amazon Alexa and Google Assistant.
The SmartThings Community Team