Plugin stopped working

Hello

The plugin stopped working suddenly. I had a sidebar cart activated with an icon at the bottom left of the layout. Last time I checked my website it was working perfectly but now I suspect that the whole plugin stopped working and not just the menu because I have “Ajax Add to cart” activated and this feature is not working anymore as well.

How to fix this issue? Maybe it’s a bug? I did not do any modifications to the website, neither did I install new plugins or themes. Everything was working but suddenly stopped.

The page I need help with: [log in to see the link]