Grey line appears in preview mode, and pictures moved upwards

Hi,

I have encountered a strange problem when using Articulate Storyline. During editing, everything seemed fine until I have previewed it. A grey line appeared at the bottom of the editing area, and pictures included in my training material have moved upwards a little bit. I have published the material and the problem affected that version as well. This is not the first time I have previewed or published the material, so this has happened pretty much without warning.

I have tried to reset the story size, to no avail. The training includes a quiz and results slide, which I have created just before the problem arose.

I have a pretty strict deadline, and would appreciate any help or idea.

Thank you for your time.

Edit: The problem might have been that the Current Player had been changed mysteriously to the other option.

Now I set the correct one and it looks fine... I hope this will solve permanently.

Edit2: Thanks for your help, luckily, the problem was not that big

Next time I'll check that page as well!