If you have a USB dongle (physical key), but Polyboard says "No license found": The USB port might be dead, or the drivers are corrupted.
You have a code, but the software rejects it. Do not panic. Here are the top 5 reasons for failure.
Some aggressive antivirus software blocks Polyboard’s "phone home" activation ping.
Although many codes are case-insensitive, Polyboard's algorithm is strict. Ensure you aren't confusing 0 (zero) with O (the letter), or 1 (one) with I (eye). Solution: Copy the code from your purchase email and use Ctrl+V to paste.