Cant save changes

I have a problem with this plugin when I try go to settings and change some stuff then click save changes it says:

WordPress has a built-in feature that detects when a plugin or theme causes a fatal error on your site, and notifies you with this automated email.

In this case, WordPress caught an error with one of your plugins, Seraphinite Accelerator (Extended, limited).

What is causing this if you have any idea, im checking the defer delay setting because im not sure if it does what I need but I want to run JS on my website and not have a delay because its needed.