Browsers will prevent audio or video from automatically playing, so clicking the start button is a requirement to get your eLearning course to run. There are a few solutions for replacing the boring grey slide with a play button, but I like to design my own custom slide to serve this purpose. As long as there is no audio or multimedia on the first slide and you select Autoplay in the Preferences / Project / Publish to Computer section, you won’t see the grey screen but instead your own design.