[simonbennett]

Holy Cow!!!

This fixed it…

https://wordpress.org/support/topic/sidebars-in-widget-admin-area-not-expanding-or-collapsing

“I can’t able to fully understand your problem but I have some solution may be useful to you. Your Problem is may be of WP_MEMORY_LIMIT.

in wordpress root folder open wp-includes/default-constants.php
on line define(‘WP_MEMORY_LIMIT’, ’32M’);
change it to 64M or more.”

[simonbennett]

Clearing cache makes no difference and there are no errors. Could be a WordPress issue I guess. Just wondered whether anyone had encountered anything like this before.

Thanks anyway, Paul.