Have a smartthings hub STH-ETH-200, all was working well except we renovated the property for a good 10 months and hub was off, when switching back on, it was removed automatically from my smartthings account, Now cannot re add it as not have the welcome code.
ST Staff are generally only available Monday-Friday on the Community forum. If you need it over the weekend, use the app to contact Support. Tap on Menu and select Contact us. They will need the serial number of your hub.