Storyline 3 grey line appearing in player

I have just moved from Articulate 360 to Storyline 3 (I was using a trial version of Articulate 360). For some reason when I publish files for the LMS in Storyline 3 (that were developed and published in Articulate 360) they have a thin grey line at the bottom and the right hand side (screenshot attached). This is only happening when viewing in Chrome - not Firefox, Microsoft Edge or IE.

I have double checked the player settings and there is no reason this line should be there. It isn't in any version I published using Articulate 360 - it's only happening when I publish the same files, with exactly the same settings, in Storyline 3.

If anyone can provide some guidance on how I get rid of this line in Chrome that would be great.

Thanks Noel