That generally means your file size is too big and the server has a specific allowance of size. The error location is pointing to the WordPress cache.php file. This one you will need to take to the WordPress.org support forums. I know many people over the years experience this kind of thing so there will be posts relating to your issue. Do a search in their forums for:
I honestly wish I could help on this one, but I’m not sure….it won’t be the theme. Other people have encountered this kind of error on WordPress, which is why I recommend searching for that issue on Google but also the wordpress.org forums and you will see many and also find what they did to fix it. I’m actually amazed at how many do experience this.
With our premium themes, we offer access to site documentation, video tutorials and timely support. Even if you have just started on WordPress, our support staff have the patience to help you create appealing sites gracefully.