Discover theme error msg on homepage/browser errors

Hello

I am using the free Discover theme on WordPress and thought I had finished the site – I then upgraded to the latest version of the theme and there are various issues I need to address. I am not a pro at wordpress and I am building this for a charity so I could REALLY use some help. Thanks.

1) Main slider issue – I tried to change the number of slides from 2 to 1 as it was before I upgraded. There is no homepage images and simply has this message

Parse error: syntax error, unexpected ‘;’ in /home/natalie/public_html/greenislandschool.com/wp-content/themes/discover/element-slider.php on line 8

How can I resolve this? Is it code I need to add to the style sheet? If so can some advise where? Thanks.

2) Aside from the above all seems fine on Google Chrome, IE homepage is completely messed up with the image links at the bottom different sizes – it looks very messy.

How can I ensure the theme is compatible to all browsers?

The site is here if that helps – https://www.greenislandschool.com

Thanks in advance to anyone who can guide me
Natalie