To complete the migration process, your app has to be disconnected from Xero first. Follow the steps outlined below.
Step 1 - Login to Xero and go to Settings
Login to Xero, and click on your company name in the left top. Open "Settings" as outlined in the screenshot below.
Step 2 - Go to Connected Apps
Go to "Connected Apps"
Step 3 - Find the Dataswitcher app and disconnect
Find the Dataswitcher app in the connected tab, and click "Disconnect".
Step 4 - Confirm the disconnect
You do not have to select a reason, confirm the disconnect by clicking "Disconnect app".
The process will automatically continue after you have disconnected the app.