Page Unresponsive when trying to access (Click) into the Widgets section under Appearance option.

soongcw

I having this error when I'm trying to go into the widgets sections in my site.

I'm using Pre-build website theme - Car Parts

I have tried others Pre-build website theme before on the same site before, there is no such error except this particular one.

I have build current website with 'Car Parts" theme

thanks