How to unsupervise an iPad that has been erased back to factory default

An iPad that was properly prepared and supervised using Apple Configurator along with Apps was reset to factory default. It now contains no apps or settings. Once reactivated, have attempted to Prepare the device to enable supervision and installing of Apps, now does not. Apple Configurator reports that it is "unable to verify the supervision state".

How do I correct this?

Secondly, will the "paid-for" apps be reinstalled properly?

Thanks

Richard