This issue may be caused by several things, please refer to the following steps to troubleshoot. Step1. Ensure you have internet access when you sign up for the TP-Link ID. Step2. Confirm you have entered a valid e-mail address and password. Please do not use special characters such as &, ~, %, space, etc. Step3. If you can’t receive the activation e-mail when sign up for the TP-Link ID, please refer to the link to troubleshoot. Step4. If the e-mail address you entered has been registered already, try to log into the Deco app directly. If you forget the password of the TP-Link ID, here is the instruction to create a new password.