Monetize your HTML5 games with GameMonetize.Com (Construct 3 plugin for the GameMonetize SDK).
After adding the Gamemonetize sdk and putting ads in my game I was getting was a black screen on preview when using the gamemonetize sdk for Construct 3. I had changed worker mode to no, but was still getting the black screen. But then I closed Construct 3 and went back to it later and everything was working fine so maybe I had to close it for the worker mode to update. I don't know, but everything is working okay now.