HSTB

But if I do that, the look and functionality of our website will be lost. We have a custom-created theme and all the plug-ins are integral to the site.

Thanks for the response. I tried to upload the file you sent and got this message:

Destination folder already exists. /data/25/2/28/128/2680128/user/2943065/htdocs/wp-content/plugins/easing-slider/

Plugin install failed.