Plugin not working after the last upgrade

The widget admin page stopped working after the custom sidebars pro upgrade. It loads slowly and I can no longer drag widgets or open the dropdown menus. Import and export is not visible and only one of the 9 custom menus are showing. I have tried to deactivate and activate. When deactivated the admin widget page works normal. No other new plugins have been installed since this upgrade and there were no conflicts prior to this upgrade. Please advise.