A Store Commander license is associated to the URL of the PrestaShop backoffice where the module was installed.
If the URL of your shop changes, or if the server IP changes too, you will not be able to validate your license.
You will need to reset the license beforehand, by logging onto your account on our website www.storecommander.com > my account > my subscription.
Under your license key, you will see the 'Reset license' link that you need to click.
You will then be able to enter your license on the Welcome form that pops up when you launch Store Commander from your PrestaShop backoffice.