As the subject says, I'm running into issues when I do things like use SendMessage during an OnUnityAdsReady. I tried to use UnityEvent with Invoke, still the same. Then tried IEnumerator with "yield return null", and with WaitForSecondsRealtime .. Still complains because it's calling "IsObjectMonoBehaviour" first.. I didn't want to have to make a complete solution just to post messages to main thread but I guess I'll have to. Is there a reason why Unity Ads Listener's events must be called from another thread? Not very beginner user friendly.. Note: It works perfectly in the editor, but not on an actual android. This was a major stumbling block for me to find out my users ad rewards weren't working. Edit: Just want to mention this is the same for IL2CPP, and Mono.