IMPORTANT! - a fix if you have a PLAY button appearing at start of courses
OK, Articulate rolled out an update to Storyline and it seems that now when publishing a course, instead of auto-playing (as before) it now puts a nasty big PLAY button on the first screen.
Hopefully Articulate will roll out a fix (very!) soon.
In the meantime, I have discovered that AUDIO on the opening slide will cause this. Removing the audio, removed the PLAY button and things went back to normal.
Therefore to get round the issue, try what I did - create a tiny opening slide of a flat colour (same as your project background) and set it to be your opening slide.
Worked well for me, and thankfully I can now stop hearing screaming from my clients.