The "GDIO LICENSE ERROR" message occurs when your license file (gdio.license.txt) is either missing from the Assets\GDIO\Resources folder, or invalid/expired. It will appear in the agent overlay:

As well as the console or player.log upon startup:

Invalid or expired license @ Resource gdio.license
UnityEngine.Debug:LogError (object)
gdio.unity_agent.GDIOAgent:Awake ()


Check that your license is valid, and located in the Assets\GDIO\License folder of your Unity project.