Hi @chris_rose
You can try this, for me it was helpful:
In order to delete a Home Location that has nothing in it:
Login to IDE at https://account.smartthings.com 134
Goto Locations
If you have multiple Locations, select the invalid one
Make sure there is no Hub associated to it
Scroll to the right and click Edit
If the Default Location shows “true” (will be read only)
If it is “true”, go back to Locations and select your primary (Real) location and set the default location to “true”
Now you can edit/delete the additional Home location as it will automatically be set to “false”.
If that fails to resolve the issue, contact ST support and they can do it https://support.smartthings.com
You can find the original thread here and the solution was from @jkp Can't delete a location keeps giving error, any suggestions?