Please read through this series of questions and use the links provided to help us narrow down what the error is and how to fix it. Please take a look at these questions and directions to ensure that you have first taken the correct path to access i-Ready.
Which type of device are you using, a PC or iPad? (an iPad requires an app to be downloaded in order to operate)
In order to get to the i-Ready program, you must first log into NCEDCloud. Here is a directional to help you get there. For PCFor iPad