Highend Theme Options don't work…

Hi there, For some reason, in the Highend Theme Options page, I can’t toggle the various option buttons, e.g. can’t turn Breadcrumbs off, and clicking on section links, e.g. Layout Settings, Logo Settings, etc… doesn’t load those screens. It’s as if the Options page is frozen.

I’ve increased the memory to 128 and the time limit to 400 in wp-config.php, like so:
define( ‘WP_MEMORY_LIMIT’, ‘128’ );
set_time_limit(400);

That didn’t help.

There are no warnings in System Diagnostics.

I have the last versions of WP and Highend Theme installed.
Thanks!